Before a rock band gets sold to the public with a record deal they usually get bought for a song, which you can read as the record company offers them a contract for a hit song or, more in the spirit of this band, they get offered a low figure to sign, meaning the record company buys their music for a song.
Before a rock band gets sold to the public with a record deal they usually get bought for a song, which you can read as the record company offers them a contract for a hit song or, more in the spirit of this band, they get offered a low figure to sign, meaning the record company buys their music for a song.