Cover (of a musical work) – A cover is a performance or recording of a song made famous by another artist. Creating a cover song requires permission from the original copyright holder(s) in the form of a mechanical license.
Using covers of famous songs is a popular practice in synch licensing. For one, it can create a feeling of familiarity whilst still being new and fresh. Secondly, it is often cheaper to license a cover of a famous song instead of the original recording. This is due to the fact that the client will only need to license publishing rights from the original rights holders and will license the master rights from the cover creator (who will typically charge a smaller fee).