Sum 41 is a Canadian rock band formed in 1996 in Ajax, Ontario. The group is known for its blend of punk rock, pop punk, and alternative rock styles. The original lineup included lead vocalist and rhythm guitarist Deryck Whibley, lead guitarist Dave Baksh, bassist Cone McCaslin, and drummer Steve Jocz. The band gained popularity in the early 2000s with hits like "Fat Lip" and "In Too Deep," featured on their debut album, All Killer No Filler. Over the years, Sum 41 has released several albums and continues to tour, maintaining a dedicated fan base.