Gavin Petrie Band 20th Anniversary Show

I don't have reliable information about a musical artist or band specifically named "Gavin Petrie Band 20th Anniversary Show" in my training data. This appears to be either a very local/regional act, a recent project, or possibly a specific concert event rather than an established artist with a documented history. I'd recommend checking local music venues, the artist's official website, or music platforms like Spotify or Bandcamp for accurate biographical information.