Prefuse 73 (Guillermo Scott Herren), is a hip-hop and electronic producer/artist, currently based out of Barcelona and signed to Warp Records.

Herren releases music under various aliases, most notably Prefuse 73, Delarosa and Asora and Piano Overlord and Ahmad Szabo. He also performs with Eva Puyuelo Muns as the group Savath & Savalas.

He began his career DJing at MJQ, a small night club in Atlanta, and then began working in commercial studios but soon branched out into his own music. Herren's first major release was under the Delarosa and Asora moniker in 1997 with Sleep Method Suite, with his latest work currently being the Prefuse 73 full-length album, Preparations[which included a bonus disc of purely orchestral ambience dubbed "Interregnums." This disc being Herren's first time ever composing for a full orchestra.]

In 2000, Herren released a CD/LP on Hefty Records/Warp Records titled Folk Songs For Trains, Trees, And Honey. This followed by a 2001 exclusive limited pressing (700 copies) of Immediate Action #1 LP on Hefty.

Herren first released music under the Prefuse 73 moniker with 2001's commercially and critically successful Vocal Studies & Uprock Narratives. In 2002 the 4-track EP The 92 Vs. 02 Collection was released, but this merely bridged the gap between his debut and the 2003 release - another full-length album, One Word Extinguisher. A collection of outtakes, Extinguished was released after One Word Extinguisher showing off some of the production that was omitted from the initial full-length. Some argue that it is an improvement on the original release. 2005 saw the release of Surrounded By Silence, Herren's third album as Prefuse 73. The album features more collaborations with a variety of musicians, including many rappers, both underground and mainstream. An out-takes album based upon Surrounded By Silence is expected to be released in the future. 2007 has brought 2 more releases under Prefuse 73, one being a full length album, and the other a 4 track EP. Preperations and The Class Of 73 Bells are the titles respectively, and both were released under Warp Records.

Herren is particularly known for his unique take on the glitch style, which has attracted both a rock and hip-hop audience. He is frequently criticised by MC's for over-editing or abbreviating their additions, often to the point of incoherence.

Along with partners Peter Rentz, Carolina Chaves, Ben Loiz, Carlos Niño, and Paz Ochs, Herren has started the Eastern Development Music label. Which is descibed by Herren as,"less concerned with being "on some next shit", "blowing the fuck up", or "changing the face of anything." We're more concerned with bringing you music we think you'll feel and understand in the same way we do."