Hi niteshift, Every time you perform a cover song at a gig, really - you owe the songwriter and musc publisher a royalty. Performance rights are not givens.

The mechanical license covers the rights to produce and sell CDs which include the song as well as downloads and other cyber usage.

The free sub-license offer is for performing bands and/or vocalists who need a new song to record and promote themselves. It includes both mechanical rights as well as non-broadcast performance rights and even the use of the instrumental track.

Cheers ~ R