What kind of license do I need for a karaoke business?

You need to buy licenses from ASCAP, BMI and SESAC who will then pay the owners of the copyrights in the musical composition [the words and music] for the songs that you play in your establishment. You also need to buy the karaoke sound recordings only from a licensed source because that source has the authority to sub-license to you the rights to play the sound recordings in your establishment. [Note: Many travelling karaoke jockeys play bootleg songs which puts the establishment that hires them at very significant risk]. Good luck.

An attorney license with a specialty in entertainment law, specifically music law. Don't do this yourself. The licenses for the Karoke songs, which is likely what you mean, are just the tip of the iceberg. You have a number of entertainment law issues. For San Diego, you might try Jeremy Evans http://www.attorneyqna.com/attorneys/92101-ca-jeremy-evans-4145880.html who is more into sports law, but will be able to help you on your karaoke business and IP law issues.

First, you need to start with an attorney practicing business law to help you with the entity formation issues. Next, I agree with the other postings that you should talk to an intellectual property attorney with experience in entertainment law. Even if you buy the songs from another service or DJ, you should consult with an attorney to make sure that you're use of the song is permitted under whatever license you receive.