Kowalczyk was born in York, Pennsylvania to a family of Polish descent. He began learning the guitar at age 12. While studying in the Radio, Television and Film program at Philadelphia's Temple University, he began writing songs and performing with his first band, Portion. Portion recorded two Extended Plays and opened for Live and other bands.
In 1999 he began playing as the touring rhythm guitarist and backing vocalist for Live, a position which he held for 10 years. He appeared as a guest musician on the Live albums The Distance to Here and V and featured in the band's only concert DVD release Live at the Paradiso – Amsterdam. During his time with Live, Kowalczyk relocated to Los Angeles and formed the band Adam & the Weight, which released the album Looking Up from the Ground in 2003. By 2005 he was living in Lancaster, Pennsylvania and had recorded a solo EP, The Dream.
In January 2011, Adam became lead singer of the Lancaster-based band The Mint.