Operation Ivy was a ska punk band formed in Berkeley, California. They are well-known as one of the earliest ska-core bands, a genre that fuses elements of hardcore with ska punk. The band consisted of frontman Jesse Michaels (vocals), Tim Armstrong (credited as \"Lint\") (vocals/guitar), Matt Freeman (credited as Matt McCall) (bass/backing vocals), and Dave Mello (Drums/backing vocals). The band\'s name, previously abandoned by another Gilman group, Isocracy, was derived from the Operation Ivy series of nuclear tests.