Under a staff writer deal, the writer is paid on a weekly or quarterly basis. An ESWA can be either tied to a record contract or independent of a record contract.(3) Co-publishing Agreement ("Co-pub"): The co-publishing ("co-pub") deal is perhaps the most common publishing contract. Musical composition can refer to an original piece of music, either a song or an instrumental music piece, the structure of a musical piece, or the process of creating or writing a new song or piece of music. The word "song" is widely misused by people in the popular music industry to describe any musical composition, whether sung or played only by instruments. People who create new compositions are called composers in classical music. In popular music and traditional music, the creators of new songs are usually called songwriters; with songs, the person who writes new words for a song is the lyricist. I am not talking about loops and canned music that lets you pretend you are on a writing streak, I am talking about a program that enables you be the architect of your own music while it takes care of (the execution of notes) the brick laying.". Composers are not limited to writing only for instruments, they may also decide to write for voice (including choral works, some symphonies (e.g., Beethoven's ninth symphony, operas, and musicals). Composers can also write for percussion instruments or electronic instruments. (c) This Agreement contains the full and complete understanding among the parties hereto, supersedes all prior agreements and understandings, whether written or oral pertaining thereto and cannot be modified except by a written instrument signed by each party hereto.