la pregunta no tiene sentido... pero creo que la he entendido.
a songwriter writes the song- the song is written by a songwriter
a record producer buys the song-the song is bought by a record producer
musicians play the backing track- the backing track is played by musicians
a singer sings the words- the words are sung by a singer
they sell the cds in music shops- te cds are sold by them in music shops* esto es una excepción ten en cuenta que los lugares siempre van al final. espero que sea esto lo que necesitas y te sirva, chao.