Lesser or J Lesser is the stage name for Jason Doerck (born December 19, 1970), a musician known for his unrepentant approach to sound creation.

Born and raised around California, including Willits and San Diego, Lesser began his music career listening to, and playing, black metal and punk. In San Diego, he had a job coloring New Kids on the Block comic books using computers.

An interest in electronic music drove Lesser to begin work with Vinyl Communications, adding more electronic flavor to what was otherwise a punk record label. Lesser's early electronic music influences included Luke Vibert's Plug alias, which Lesser admits he tried to imitate with poor success.

Lesser settled in the San Francisco Bay Area in 1994, where he participated in the drum and bass scene. There he toured with A Minor Forest, and later collaborated with Kid606, publishing a number of records on his Tigerbeat6 label. In addition, Lesser has played with Crash Worship.

Lesser became an honorary member of Matmos when they toured with Björk as an opening act in addition to playing as supporting musicians in her band on her Vespertine tour in 2001. Later in 2004, Lesser remixed "Who Is It" from Björk's "Medulla" album.

In 2001, his album "Gearhound" won an Honorable Mention for Digital Musics in the Prix Ars Electronica.

In 2002, Lesser published a CD entirely in MP3 format - LS-MP3CD-R. This project included hundreds of MP3s from his prolific musical history, dating back to his first band "The Robotic."

J Lesser is currently a member of the laptop group Sagan with his wife Blevin Blectum, Wobbly, and video artist Ryan Junell.