Born and raised in New Orleans, Pretus began playing drums at the age of 9, and guitar at the age of 13. In 1997, he started his first band, All She Wrote, in which he played drums. In 1999, he joined the band Climate Control, playing drums and singing backing vocals. Several of the band's earlier shows at The Neutral Ground coffee shop were shut down due to the packed crowd breaking the firecode. They released a full-length CD, "Clutch," and in 2001, recorded a 4-song ep, "The Timely Demise of Climate Control," which was released for free online in 2007.
While attending Louisiana State University, Jonathan switched to guitar and lead vocals in the band tWeezer, a Weezer cover band. They won the 2001 LSU Battle of the Bands and opened for such acts as Stroke 9, and The Verve Pipe. Also during this time, Pretus played in the short-lived Monophonic, which featured the Pretus-penned "Waiting To Fall" on a compilation of up-and-coming Louisiana artists.
In 2005, Pretus was a co-founder of New Orleans band The Garden District, in which he wrote, was co-lead vocalist, and rhythm guitarist. The group toured the Southeast, including a stop at the 2006 South by Southwest Festival. In late 2006, the group released their debut ep, "So Much It Hurts," which was produced by Fred LeBlanc of Cowboy Mouth and Tom Drummond of Better than Ezra. While the band leaned more towards the "emo" tag, Pretus' songs, such as "Avalanche," "Intrepid Inventions," and the live favorite "So Low," focused on a more straight-ahead, melodic rock approach.
2007 saw Jonathan wearing several different hats, including, but not limited to: bowlers, fedoras, ballcaps, and berets. In addition to Garden District duties, he toured with Cowboy Mouth for several weeks early in the year, filling in for Vance DeGeneres. In April 2007, he left The Garden District to pursue other musical paths and ended up joining Cowboy Mouth in August 2007. Since then, he has participated in the recording of the band's most recent album "Fearless," contributing guitar tracks, vocals, and keyboard parts. In addition to writing his own music, he began working on bed music for independent films and commercials. Some of his music was used in a not-yet-released film called LA Sky.
In 2010, Pretus parted ways with Cowboy Mouth and is working on his next musical venture The Breton Sound with band partner Stephen Turner. They quickly produced an ambitious EP, Eudaemonia. The EP, Maps, was released in 2013 and they are currently working on their third album.
Pretus is also a visual artist, with his usual medium being acrylic paint. He often paints on canvas, guitars and drum heads.