Your particular requirements for the use of the music will dictate the type of license you will need. In all cases, however, you will have to contact the copyright owner or the person who controls the rights to the composition. If you are using a sound recording, you music obtain a license from the owner of that specific recording. There is a distinct difference between a Synchronization License and a Master License, requiring two separate negotiations. If you need the master rights, you must always secure the synch rights along with it.
Most composers feel very protective about their songs and rightly so.
If it is your intent to make any lyric changes, or any adaptation of the music, you must first get permission from the copyright holder. This will, more than likely, necessitate obtaining permission directly from the composers, their management, their attorneys or their estates. Parody lyrics must go through the appropriate approval process before incorporating them into the song. It is extremely important that you have a clear idea of the nature and scope of the terms that you need. Once it has been determined what type of license is required for your project, the task of clearing the music and negotiating the license begins.