How much does it cost to copyright a group of 5 songs?

It is possible to register multiple works, such as songs, on a single application filed with the United States Copyright Office so long as the ownership of the copyright is the same for all of the songs.  In addition, the songs must have been "published" (made public) on the same date. If those conditions are true for the 5 songs, you can put them on a single application and pay a single registration fee. However, there is one catch. If there is infringement of just one of the 5 songs, you could be limited in the amount of "statutory damages" you would be entitled than if you had registered each song separately. Additionally, if the same entity owns both the sound recording and the lyrics, it is possible to register them in one application.