Tagg moved with Brent Bourgeois to California's Bay Area, and in the late 1970s they played in a Sacramento band called Uncle Rainbow, which included members from Texas and other parts of the South. In 1984, they moved to Sacramento and formed Bourgeois Tagg with guitarist Lyle Workman, drummer Michael Urbano, and keyboardist Scott Moon. Bourgeois played keyboards, Tagg played bass, and they both shared lead vocal duties. They released a self-titled debut album in 1986, which produced a hit single "Mutual Surrender." The following year, they released their second album, Yoyo, which was produced by Todd Rundgren, and had another hit, "I Don't Mind at All," which reached the Top 40 on the Billboard chart. During this period Bourgeois struggled with addiction to drugs and alcohol. When fellow musician and drinking buddy Charlie Peacock began going to church, Bourgeois followed and became a Christian. Latent conflicts became exacerbated by Bourgeois' trend toward Christian lyrics and the band split in 1989 while working on a third album. The band members appear on Rundgren's 1989 album Nearly Human, and they toured as part of Rundgren's backing band. Tagg also played as part of Hall & Oates touring band.
Staff songwriter
During the 1990s Tagg worked as a staff songwriter for Warner/Chappell Music. Some songs he wrote were recorded by, Eddie Money, Lee Ritenour, Jenni Muldaur and others.
Solo recordings
Tagg released two solo albums: 1995's With a Skeleton Crew and 1997's Rover. All five members of Bourgeois Tagg appeared on With a Skeleton Crew, with all but Scott Moon playing on the track "1/2 Yes, 1/2 No." Tagg has said that the song was written for the third Bourgeois Tagg album that never materialized, so with Lyle Workman's help, he recorded the song himself.
By the mid-90s Tagg had a family, and no longer wanted to remain on the road. He became an English and drama teacher, and lead teacher of the arts academy, at Hiram W. Johnson High School in Sacramento. He began writing in his spare time and has written numerous books on Abraham Lincoln. He taught English, literature, and creative writing at C.K. McClatchy High School in Sacramento, CA until retiring in 2017 to conduct more research on Lincoln.
Historian
Tagg has written a number of books on Civil War history:
Described by a reviewer as "a thumbnail sketch biography of each of the infantry commanders who took part in the battle, from the brigade level up. ...should find a home on the bookshelves of those readers whose special interest is Gettysburg."