There are a few things that you could mean. Phonogram was a Record company (Phonogram Records) that merged with Polydor. It is also a comic book written by Kieron Gillen and Jamie McKelvie. The third thing a Phonogram could be is a grapheme that represents phenomes and phenome combinations.
it is a music of the given song without lyrics for someone who wants to sing the song. just like Karaoke but no lyrics given.