Lonnie joined Petra in 1996, replacing Ronny Cates. He helped record some of the bass for Petra's second praise album, Petra Praise 2: We Need Jesus. After that, he immersed with the band in the creation of their next studio album. Along with fellow newcomers to the band, Pete Orta and Kevin Brandow, he contributed (along with Petra's founder and songwriter, Bob Hartman) to the songwriting of Petra's album God Fixation in 1998. After Petra's 2000 album, Double Take he left to join TAIT. Chapin won a Grammy award in 2001 for Gospel Rock Record of the Year with Petra and three nominations. He is also an inductee in the Hard Rock Cafe in Orlando Florida and Cape Town South Africa.
Lonnie was invited to audition for Tait by his brother, Chad. When Michael listened to him, he liked it so much that he asked him immediately to stay in the band. Tait would bring Lonnie another Grammy nomination and Dove award. He remained in the band until 2004.