Ian Osterlitz has seen Sum 41 1 time.

Sum 41 is a Canadian rock band originally formed in 1996 in Ajax, Ontario. The initial lineup consisted of Deryck Whibley on vocals and guitar, Dave Baksh on lead guitar, Jason "Cone" McCaslin on bass, and a rotation of drummers before settling on a long-term member. The band achieved mainstream popularity with their unique blend of pop-punk and alternative rock, particularly with their early albums such as "All Killer No Filler," which features enduring hits like "Fat Lip" and "In Too Deep." Over the years, Sum 41 has evolved its sound to include elements of punk rock, heavy metal, and even hip-hop. The band's discography boasts multiple albums that have received both commercial and critical acclaim. Known for their high-energy live performances, Sum 41 has amassed a dedicated global following and has been honored with various awards and nominations, including a Juno Award and Grammy nominations.