I love people who actually do this sort of thing, in the same way I love the people that send John Oliver actual 50 pound bags of seed.
FOIA is not used to obtain information contained in the seized material, but information that arose during the investigation. If for some reason, the information created in the investigation contained the actual recording from the album, then you could at least theoretically ask for that information. If not, then there was no information to ask for in the first place.
What can I ask for under the FOIA?
A FOIA request can be made for any agency record. You can also specify the format in which you wish to receive the records (for example, printed or electronic form). The FOIA does not require agencies to create new records or to conduct research, analyze data, or answer questions when responding to requests.
Seems like it's unlikely that you can just FOIA arbitrary data from a CD or hard drive that's been seized during an investigation though.