You play the piano, you want to be found in Google Music or creek into Google.com for a music OneBox result? Then you need to learn how to get into the Google Music Search index. A thread at WebmasterWorld discusses just that. One member said that "it looks like some of their reviews are from Epinions." Tedster (WMW Admin) said he heard that "Google's Music Search essentially uses crawled information. PR of any crawled content is a big factor, plus they have some "special sauce" in the music search algo." But there may be an easier way, according to Google blog post in December 2005, it says "would like to be listed?" and they link to the Google contact form.
Forum discussion at WebmasterWorld.