Formed in November 1981, Black 'n Blue played gigs in the Portland area for over a year before making a move to Southern California in early 1983.

[4] The band traveled to Germany in early 1984 to work with Scorpions producer Dieter Dierks, releasing Black 'n Blue in August 1984, featuring the songs "Hold on to 18" and "School of Hard Knocks", both co-written by Thayer and St. James.

The follow-up Bruce Fairbairn-produced album, Without Love, was released in 1985 with Thayer, St. James and Jim Vallance co-writing the single "Miss Mystery."

In October 2010, the band was inducted into the Oregon Music Hall of Fame in Portland,[6] with all five members of the classic lineup (including Thayer) attending.

In 1992, Thayer joined Los Angeles rock band Shake the Faith and recorded the album America the Violent, which was released in Japan in 1994.

In preparation for 1996's Kiss Alive/Worldwide Tour, Thayer worked with guitarist Ace Frehley and drummer Peter Criss, to help them relearn their original guitar and drum parts from the 1970s.

[12] By 2002 and with the growing uncertainty of Ace Frehley's involvement in the band, Thayer stood by for a Kiss performance at the 2002 Winter Olympics Closing Ceremony in Salt Lake City to fill-in on lead guitar if necessary.

One month later, Thayer got the call and donned the Spaceman makeup for the first time, filling in and performing onstage with Kiss at a private concert in Trelawny, Jamaica.

Recorded and filmed in front of 40,000 fans, a pay-per-view, Kiss Symphony: Alive IV CD and DVD were released worldwide later that year.

"[15] A new Kiss studio album, titled Monster, was released in October 2012; Thayer co-wrote 10 songs and sang lead vocals on "Outta This World".

"[18] When reminded that he was the youngest member of Kiss, Thayer spoke on his plans post-Kiss, revealing, "I’m not completely ready to retire yet; I have ideas and certainly options on the table.

"My new White Lightning signature model is the pinnacle of looks, style and flash," Thayer stated, "I'm proud to put my name on a serious guitar that can be enjoyed at home or rock the biggest stages in the world.

In February 2010, Thayer and Kiss were featured in ABC's Extreme Makeover: Home Edition helping a family in need with new instruments for their home-based, non-profit music school.

[26] Kiss headlined Rockin' the Corps, an outdoor concert in 2005 at Camp Pendleton, California dedicated to US Marines and US Military personnel stationed in Iraq and Afghanistan.

The exclusive summer party at a private residence in Lake Oswego, Oregon featured an appearance and acoustic set by Kiss.

"[34] At its May 2018 commencement, Pacific University honored Thayer with an honorary doctorate of humane letters "in recognition of his tremendous career and philanthropic leadership efforts.