As a teenager, as part of the duo the Whooliganz (with Scott Caan, son of James) and the greater rap collective the Soul Assassins (with Cypress Hill, House of Pain, etc.), he released the single "Put Your Handz Up" on Tommy Boy in 1993, though the Whooliganz' debut full-length, Make Way for the W, was eventually shelved. The Alchemist continued making beats, however, working with and learning from DJ Muggs on 1995's Cypress Hill III: Temples of Boom as well as with childhood friend Evidence of Dilated Peoples.

After moving to New York to attend college, Al hooked up with Queensbridge duo Mobb Deep, producing the songs "The Realest" and "Thug Music" from their 1999 record Murda Muzik, a collaboration that led to work with Pharoahe Monch, Royce da 5'9", Fat Joe, Defari, Freddy Foxxx, Ludacris, Big Daddy Kane, and Ghostface Killah, and even rock acts like Linkin Park and Morcheeba. In 2004, the Alchemist released his first solo full-length, 1st Infantry, which, besides featuring his own beats, also had him rapping alongside Stat Quo, the Game, Lloyd Banks, Mobb Deep, and Dilated Peoples, among others, and in 2005, after Eminem's DJ Green Lantern left the Anger Management 3 tour, the Detroit rapper hired Al as his replacement.

In 2006, the Alchemist showcased his work with a pair of mixtapes of previously released and unreleased material, The Chemistry Files and No Days Off. After releasing the instrumental collection Rapper's Best Friend in 2007, 2009's Chemical Warfare featured Eminem, Juvenile, Dilated Peoples, and the Lady of Rage. The year 2012 found him releasing Vol. 2 of Rapper's Best Friend along with Vodka & Ayahuasca, a collaborative album with producer/rapper Oh No recorded under the name Gangrene, and Russian Roulette, an album built by sampling Russian music. A year later he worked with Prodigy on the album Albert Einstein, while 2015 saw him collaborate with Oh No on Welcome to Los Santos, a collection inspired by the virtual radio stations found in the video game Grand Theft Auto V. Featuring samples from Israeli radio and thrift store albums the producer bought while visiting Israel, the beat tape Israeli Salad was also released in 2015. ~ Marisa Brown