Apple is inviting selected iTunes Music Store users to answer a questionnaire about the service.

Macworld has learned that questions revolve around demographic information, ease-of-use and satisfaction. It appears that only a small group of users are being polled at present.

The survey concentrates on the service's existing features, and user satisfaction with these. "Do you use iMix?", for example.

When addressing new features, Apple plays its cards close to its chest, though one question promises to address a much-requested feature, Apple asks users if they would prefer to be able to download songs they have purchased more than once. This would make it easier to buy a song at work and home, or to share collections between legally-authorized machines.

As a reward for participating in the survey, respondents are being awarded a free song download.

What do you think of the iTunes Music Store? Which features do you use, and how happy with them are you? Are there any features you would like to see added to the service? Let us know on Macworld's Forum.