The Google Doodle you see here is not to celebrate anything besides a rumor that Google may be working or launching a new Music service, perhaps to be called Google Audio.
[Update]: for further information, check out Google Music.
Not much official information has been provided whether this new Google Music service will be like the Google Music in China, which has provided free downloadable tracks since 2008.
We can hope that this Google Audio rumor is actually true and is surfacing in time with Google Android getting a little more popular. Maybe it is just in time to be integrated with new Android phones, so people will have other considerations to Google cellphones.
Well, until we have more information about the rumored Google Music or Google Audio, you would have to be satisfied with their actual current ongoing project of Google Wave. By now you hopefully already received an invite, have tested the Wave Preview, and are part of the many helping shape it to a better service.