The Asteroid Smart supports music playback from USB, Apple devices, SD cards, and the radio. File support includes standard MP3s. Lossless FLAC/OGG is not supported natively, though this can be circumvented by using VLC. You can access and play back audio based on track information, folder, or from a list of all accessible files. CD covers are displayed on-screen if there's an image inside the containing folder. Parrot's native app works fine, though we tended to use Spotify for streaming and VLC for FLAC playback.
We attempted to connect a 500 GB portable USB hard drive loaded with 400 GB of music, but were stymied by the playback app's folder and file limit. This isn't an issue limited to Parrot; we've seen the same behavior from many OEM systems, too.
If you can't live without SiriusXM satellite radio, you'll need to side-load the streaming app or attach a portable receiver to the line input, since the Asteroid Smart doesn't have built-in satellite radio support and Parrot doesn't sell an add-on tuner. Personally, this isn't a problem for me. Parrot does provide the Spotify app, and I'd rather pay $10 a month for that. Alternatively, you can side-load Pandora or another Android-based music app.
Voice commands on the Asteroid Smart work with your phone contacts and music playback. The included stereo mic is excellent, and we had zero issues navigating our contacts while driving. Stepping through a music collection is also pretty easy (unless of course you hook up a big fat external hard drive that can't be indexed). We weren't expecting it, but voice search works with Spotify too, allowing you to find artists and songs without taking your hands off of the steering wheel. That's a nice touch.
Not all is perfect, though. Our older test vehicle has a voice command button that successfully activates the voice command feature, but you have to manually choose whether you want to search through music or phone contacts through the touchscreen, somewhat defeating the purpose of the steering wheel button. Ideally, you'd want the button to bring up the menu and then prompt you to speak your selection.