Shoutcast maintains a radio directory of 50,000+ radio stations from all around the world. The company, owned by AOL, released its first Shoutcast API a few years ago, but has since released version 2.0. The updated API provides developers with more advanced options for integrating music streaming services into web services and mobile applications using RESTful calls formatted in XML, JSON and RSS.
Gracenote "touches hundreds of millions of music fans and TV viewers everyday. The Gracenote database is the largest source of music and video metadata on the planet, featuring descriptions of more than 130 million tracks and TV listings for 28 countries." Recently, Gracenote launched a developer program that opened its Gracenote API to the developer community. The API delivers Gracenote's rich music metadata to any connected app.