Gammer made his first appearance in the hardcore scene during 2002 and since he has gone on to be a very successful and prolific producer, being best known for his extensive discography on the revamped Essential Platinum label. A large proportion of his tracks on the label are collaborations with the label's founder Dougal, though he has also had solo releases and appeared alongside other artists such as G. Spencer, and DJ Seduction. Gammer is considered one of the leading artists in UK hardcore. Aside from his vinyl and digital download releases, his music appears on many albums, including the highly successful Bonkers series.
In April 2007, Matt Lee started his own label Muffin Music, and released a promotional mix for it.
Some of his latest releases include Feel the Bass, Dougal and Gammer's remix of Faith by Bliss Inc, and Nobody Likes The Records.