From "Music Technology" magazine January 1987.
Although the review is based on the Spectrum version it looks similar enough to the CPC version to be of interest:
http://www.muzines.co.uk/articles/ram-music-machine/223 (http://www.muzines.co.uk/articles/ram-music-machine/223)
CPCWiki entry:
http://www.cpcwiki.eu/index.php/Music_Machine