The Mac is immensely popular for music professionals, but the introduction of low-cost or free software means even enthusiast musicians can now make music on their Macs.

Macs have always been good for music, but Mac OS X's powerful audio capabilities and Apple's acquisition of German music software company Emagic make the platform an unassailable musician's choice: Emagic's expertise is in-house for developing applications like GarageBand and Soundtrack. So what else do you need for basic Mac music-making?

The basic list requires a master MIDI keyboard, a MIDI interface, an audio interface, a good microphone, a microphone preamp (if your audio interface lacks one), and a listening system. This could be a HiFi or dedicated studio-monitor speakers. If you need to employ an external stereo recorder, you'll a need built-in CD burner.

While basic MIDI sequencing systems that use hardware synths don’t overly tax the host computer, MIDI-only software can't record audio – so you can’t add vocals or guitars. With added audio capabilities your Mac moves beyond MIDI and becomes a software simulation of a complete professional recording studio, with mixers, effects and more. To use it effectively, you need to know how a traditional recording studio works, so magazines like Sound On Sound (of which I am Editor-in-Chief) are valuable.

If the idea of a steep learning curve is daunting, GarageBand provides exceptional functionality wrapped-up in an approachable interface.

For audio, anything under a 933MHz G4 is probably a bit underpowered for serious audio work, as software MIDI instruments take a more processor overhead than simple audio. The latest machines, such as G5s, are fast and powerful – and though there still comes a point beyond which they can’t perform any more consecutive tasks, these machines set the performance bar very high. Computing power limits the number of audio tracks you can record or playback simultaneously and/or limits the number of virtual effects and instruments you can use at one time. In the case of virtual instruments, the general rule is that the more 'voices' (different notes) you play at once, the more processor power is used.

Once you have your Mac, it's worth adding memory – especially if intending to use software samplers, as most store all their sounds in RAM. An extra 512MB or more is ideal. You will also need to choose a suitable MIDI interface to connect a MIDI master keyboard, an audio interface that meets your needs, and suitable music software.

Those who choose a new machine will find that GarageBand comes as part of the iLife suite of programs, and provides a straightforward yet powerful means for newcomers (and the more experienced also seem to like it). It makes it easy to experiment with software instruments and effects, multitrack recording and mixing. At time of writing, GarageBand can only support software instruments (it has no MIDI Out), and is lacking some of the features of a powerful sequencer such as Logic or Cubase, but it can accept third-party AU (Audio Units) effect and instrument plug-ins and includes some powerful tools for loop manipulation. It can also load audio loops designed for use with Apple's SoundTrack program. If your current machine runs OS X but you don't have iLife, it can be purchased for only a modest cost.

The mainstream audio/MIDI music software packages are Emagic's Logic, Cube SX, ProTools LE and MOTU's Digital Performer. Where one than one software version is available, you may find that you can get a much cheaper version with less complexity and less functionality than the high-end, high-price version, but that will still do everything you need. For example, Emagic supplies Logic as the all-singing Logic Pro or as the much cheaper but still very capable Logic Express.

If you have friends who work with a specific software sequencer, then you might want to use the same as them so that you can collaborate on projects more easily. Friends are also a good source of free tech support – and if you're a newcomer to music software, you’ll probably need some help to get started.

My own preference is to use a sequencer that supports VST and/or AU plug-ins as there's a good selection to choose from and they tend to be the most cost-effective formats. Other than your sequencer, you may also wish to consider a dedicated stereo audio-editing package such as Bias Peak, as these generally make editing easier than trying to do the same job in your sequencer – though it can be done. Roxio's Jam is also an excellent choice for creating music CDs once you've done the editing at it can be used for creating masters for duplications and it has all the facilities you need while being simple to use.

Once you have these basic items, you'll also need a master MIDI keyboard and a pair of reasonably accurate speakers (plus amplifier) for monitoring purposes. A master keyboard has no sound-creation facilities of its own, as a synthesizer has – its job is simply to generate MIDI note information when you play. Most have conventional MIDI Outs on 5-pin DIN connectors, but some also include a built-in USB MIDI interface. Providing this is OS X-compatible, you can dispense with the hardware MIDI interface unless you also need to connect a number of external synths and/or MIDI control surfaces. Indeed, some controller keyboards even come with MIDI control surfaces built in. These are essentially physical knobs and sliders that send MIDI controller information, so you can use them to adjust various functions within your music software, such as track levels, pan positions or virtual instrument and effect parameters. This is particularly useful for anyone into making dance music as twiddling synth controls in real time is de-rigeur!

MIDI controller keyboards are available in all sizes, from two octaves to seven octaves and with either full size or three quarter size keys. All worthwhile models will include MIDI velocity (the harder you hit the keys, the louder the synth sounds) and some may also offer aftertouch, which uses a pressure sensor below the keyboard to send MIDI control data when you press down on the keys. If you're a serious piano player, you can also pay more for a master keyboard with a weighted, piano-like action.

If you don’t intend to use an external mixer and your master keyboard doesn't include a MIDI controller section, then consider adding a hardware MIDI control surface to drive the mixer section of your sequencer. If you do, I'd advise you pick a model with moving faders as these are becoming less expensive and are the easiest type to use.

The audio interface
As intimated already, some Macs come with audio inputs and outputs already built in and some may even have integral microphones, though some only have audio outs. As a rule, internal microphones are less than ideal music recording (they are low cost and also pick up drive noise) and though the quality of the internal audio may be acceptable, the latency may be higher than when using a more serious audio interfacing option. Latency is the delay heard between pressing a key on the master controller keyboard and hearing the sound of the instrument play from the Mac's audio outs. With a decent audio interface and drivers, the latency will be too small to be audible.

Most third-party audio interfaces now offer 24-bit resolution, and though CDs are still only 16-bit resolution, the quality of your recordings is likely to be better if you record and mix at 24-bit resolution, then reduce the bit depth to 16-bit as the last process you undertake before recording the audio to CD. Working at 24 bits allows you to leave a sensible safety margin when recording to prevent overloads (clipping) and also preserves more signal quality when applying effects and signal processing. Having said that, working at 16-bit resolution also produces excellent results providing you’re careful to set recording levels as high as possible without allowing the meters to go into the red.

Next, do you need your audio interface to have multiple ins and outs or will stereo suffice? If recording only one or two parts at a time and mixing everything into stereo inside the software, then you can probably get by with using a simple stereo-in, stereo-out interface, which will cost less than one with multiple inputs and outputs. On the other hand, if you plan to record multiple singers and players at the same time while recording each of them onto a separate audio track, then you'll need an interface with as many physical inputs as you wish to record simultaneous tracks. The same applies to outputs – if you intend to mix using an external mixer (which may be a good option if you need to include external hardware synths in your system), then an interface with eight or more analogue outputs is ideal. On the other hand, if you’ve no external sound-generating equipment, there's really no need for a mixer at all.

Multichannel Digital I/O is often provided alongside analogue I/O, usually in the 8-channel ADAT optical format, which is of value if you need to connect your interface to a digital mixing console or digital recorder fitted with ADAT optical connection ports. The majority of serious audio cards also come fitted with stereo digital inputs (mostly S/PDIF in coaxial or optical form). Having S/PDIF I/O is particularly useful if you’re copying audio directly from your soundcard to a hardware digital stereo recorder (such as MD, DAT or CD-R), or if you have an external digital mixer with an S/PDIF input. By the same token, an S/PDIF input will enable you to load in material from DAT, MD or CD-R for further editing, providing your source machine has an S/PDIF output. Inexpensive converters (such as the Fostex COP-1) are available for changing optical S/PDIF into coaxial S/PDIF and vice versa. Some high quality third-party microphone preamplifiers also come with S/PDIF digital outputs so these can be connected directly to your audio interface.

Audio interfaces generally connect to the computer via USB, FireWire or PCI card, though a few PCMCIA cards are available for use in laptops. USB (unless USB 2.0) devices are limited to around four audio inputs and four audio outs, though Apple/Emagic offer a 2-in/6-out model and a 6-in/2-out model that work well at sample rates of up to 48kHz. If you wish to work at the high sample rates used by some audiophile delivery formats such as DVD-A, you'll need a card that can work at up to 96kHz, and if this has USB connectivity the maximum I/O capability is likely to be 2-in/2-out. However, for most applications where the result is to be an audio CD-R, then 24-bit, 44.1kHz support is all you need to look out for. If using Emagic software or GarageBand, one of the Apple/Emagic interfaces should guarantee trouble-free operation.

Most audio hardware now works at both 16 and 24-bit resolution so you can choose which one is best for your projects. However, some hardware is limited to a maximum of 48kHz sampling rate while others support 96kHz sample rates or even higher, sometimes at the expense of using fewer audio channels at the same time. My own view is that the 96kHz sample rate has no significant sonic advantage unless you're working in a world-class studio environment – in which case you're unlikely to be reading this article. Working at 96kHz eats up your processor power and disk space exactly twice as quickly as 48kHz audio. That means you have half as many audio tracks and can run only half as many plug-ins than if you'd stuck to working at 44.1kHz.

Working at 24-bit, 44.1 or 48kHz seems a sensible compromise when working with acoustic instruments or music that has wide dynamic range while 16-bit, 44.1kHz is perfectly adequate for most pop or dance music with a limited dynamic range. If you’re working towards producing a CD, then sticking with the 44.1kHz sample rate makes a lot of sense, otherwise you have to sample-rate convert your final mix to 44.1kHz before you can burn it to CD-R.

Some USB audio interfaces are powered directly from the USB port, making power supplies or batteries unnecessary. This is attractive for laptop use – but note that bus-powered USB interfaces tend not to include microphone preamplifiers, so if you need to recording using a microphone, you'll also need a separate preamplifier.

FireWire and USB 2.0 have much wider bandwidths than USB so units with up to 24 channels of I/O are available, though the majority offer around eight channels of I/O augmented by one or more ADAT-format digital interface. Whether you can use multiple audio interfaces at the same time depends both on your operating system and the host software. Mac OS X is designed to support multiple audio interfaces but at the time of writing, Apple's own Emagic software didn't support this, even though MOTU's Digital Performer does.

PCI card-based interfaces can also offer multiple channels of I/O, though unless they have some form of external breakout box, there’s limited room on their rear panels for all the necessary connectors unless the connections are almost all digital.

About microphones
The analogue I/O on most audio interfaces is designed to accept (and to output) line-level signals, which are compatible with hardware recorders, CD players, electronic keyboards, analogue mixers and so forth. Some of the more elaborate multi-channel interfaces also include two or more channels of microphone level inputs which have three-pin XLR connectors rather than the more familiar quarter inch jack plug commonly used for instrument and line connections. Microphone inputs use low-noise circuitry and have much more gain than line level inputs to accommodate the tiny signal output from a typical microphone. They also have a different input impedance to line inputs. All serious recording hardware with mic amps built in is designed to work with low impedance microphones and will have switchable phantom power (48 volts) to enable capacitor microphones to be powered directly from the preamplifier). To make a good recording, it is essential to have an adequately mic and preamp, just as a camera needs a good lens. If the sound is degraded at source by the use of a poor quality mic, you can't recover that quality later in the signal chain.

If you wish to use one or more microphones but have chosen an interface with only line inputs, then you'll need to buy a separate microphone preamplifier that plugs into the line inputs of your audio interface. Many are available from music stores ranging in cost from under £40 to well over a grand. Where multiple microphone inputs are needed, there are several 8-channel mic preamps available with an ADAT format digital output that can be connected directly to the line inputs of an audio interface that has an ADAT input. Even the cheapest of these preamps sounds vastly better than the built in audio or mic inputs on most computers – but if in doubt, discuss your needs with a pro audio music store.
The MIDI interface
Your choice of MIDI interface depends mainly on how many external hardware synthesizers (or MIDI control surfaces) you wish to connect to the system. If all you need to connect is a master keyboard to control virtual synths, then a simple one-in, one-out MIDI interface (or the USB MIDI interface on your master keyboard if it has one) will do the job perfectly. A single MIDI port can carry 16 channels of MIDI data.

If you have more than one or two pieces of external MIDI gear to connect, an interface with between four and eight outputs may be more appropriate. As with audio interfaces, you need a MIDI interface that has drivers that are compatible with both your operating system and your audio software unless you're using Mac OS X, which includes MIDI support as part of the operating system. If you choose an interface that comes with OS X drivers, it should be accessible by any audio program that needs it. OS 9 die-hards will also need to use OMS (open MIDI System) software to run a multi-port MIDI interface unless it is one supported directly by the host software, in the way that Emagic's MIDI interfaces (MT4, AMT8 and Unitor) are supported by Logic. OMS is usually provided on the driver install CD-ROM that comes with the hardware.

There’s sometimes a further advantage in buying a MIDI interface made by the same company as your main audio application as some of these are designed to use advanced buffering in order to improve the timing of MIDI data. Examples of these are the Emagic Unitor and AMT interfaces.

Hard drives
Current EIDE drives are perfectly adequate for recording multiple tracks of audio, though my preference is to fit a second internal drive (ideally a high capacity drive with a spindle speed of at least 7200rpm) to be used purely for audio recording as you can de-fragment it easily and also keep your audio separate from your applications. You could equally use a FireWire drive, but on machines with a single FireWire port, that means sharing bandwidth with anything else that might be hooked up to the same port, such as an audio interface. In my own setup, I use an external FireWire drive simply for backing up, and if you're using a laptop, you can usually record to the internal drive without problems providing you have sufficient free space.

Audio takes up a lot of drive space needing around 5MB per track for each minute of 16-bit recording at 44.1kHz sample rates and around half as much again when working at 24-bits. Additional drives smaller than 180GB tend to be a false economy.

When recording and mixing audio, you need to be able to hear an honest representation of what you've recorded. While headphones are useful quality control tools, they don't present the bass end or the stereo imaging in the same way as loudspeakers – so including speakers in your system is highly recommended. You have a choice of active speaker (those with the amplifiers built in) or passive speakers (which need a separate amplifier), but whichever you choose, you need to buy speakers that sound honest rather than flattering. Multimedia speakers are invariably too inaccurate for serious work, though the better ones are fine if you just want to get a feel for recording. A useful tip is to check your recordings on as many different playback systems as possible to establish whether you are getting the tonal balance of your mixes too high. For example, if your mixes sound bass light everywhere except on your system, your monitors are probably bass heavy and you'll need to adjust your mixes accordingly.

Mics and preamps

If your audio interface doesn't have microphone inputs as standard, you'll need to buy a separate microphone preamplifier. Unless have pro aspirations, I'd recommend a mic preamp at the lower end of the price range and you don't need one with built in effects or other frills as you can do all that in the computer using plug-ins. Just make sure it has switchable phantom power for capacitor microphones.

The microphone is a crucial part of the signal chain, but fortunately, there any now many low-cost imported studio mics on the market that offer extremely good audio quality for very little money. Again, even if you decide to upgrade later, they will always come in useful as a second mic for when you need to record two instruments or voices at the same time. As a first purchase, I'd recommend a large diaphragm capacitor microphone with a cardioid (directional) pickup pattern. The advantages of a capacitor mic are that it produces a stronger signal than a typical dynamic stage mic and is better able to capture high frequencies, which makes it sound more natural and better suited to acoustic instruments as well as voice.

This type of microphone needs to be used in conjunction with a pop screen when recording close-up vocals (a nylon gauze panel stretched over a hoop and mounted just in front of the mic) and should be mounted on a stand rather than being hand held. All capacitor mics (other than those that use tubes) need a phantom power source – so that 48-volt button on your mic preamp needs to be turned on after you connect the mic. Phantom power isn’t an option – these mics will not work at all without power as they contain on-board electronics.

A number of innovative products have been developed to combine the functions of digital mixer, digital effects, control surface, audio interface, mic inputs and MIDI interface in a single unit, the best known probably being the Yamaha 01X. This connects via a standard FireWire port using Yamaha's mLAN data protocol and satisfies most of the hardware needs of a typical computer-based recording system. As a bonus, the O1X also includes some very worthwhile plug-ins in both VST and AU formats, though other manufacturers, such as Tascam have also developed their own take on this approach – so it's worth scanning the music mags and store adverts to see what is around. One of these devices plus a G4 laptop gives you a powerful and portable recording studio where all you need to add are microphones and monitor speakers (plus amplifier if the speakers are not active).

Setting up
The most important part of setting up a studio is to get the loudspeakers in the correct position, which usually means around 1.5m apart and around 1m in front of you, set at head height and angled inwards so the tweeters point directly at your head when you’re sitting in front of the computer keyboard. The sound quality will probably be more accurate if you stand your speakers on stands rather than on your desk, but consult the speaker manuals – they may have specific recommendations.

Most computers make some physical noise (especially their fans and drives), though iMacs and laptops tend to be quieter than most. Ideally, you should record in a separate room to your computer, but unless your system is particularly noisy, you’ll get acceptable working at the opposite end of the room with the mic facing away from the computer. Recording away from walls and with soft furnishing in the room usually sounds better than recording on a boxy or reverberant sounding room, so if your room is too 'live', try hanging a duvet behind the singer while recording.

If you start off simply and then investigate the more-sophisticated features of your software as you need them rather than trying to learn everything at once, you'll probably be recording great music in no time without tearing your hair out – though it's always best if you can get a clued-up friend to spend a couple of hours with your first. Most of the software instruments and samplers come with a huge library of sounds to get you started, so all you need are the ideas and ideally the ability to play the keyboard, even if only at a very basic level. The software and your Mac will do the rest.