 This is Fresh Air. Rock, punk, and funk. Our rock critic, Ken Tucker, has come up with examples of three genres musicians are exploring in new ways. Mike Campbell, the former member of Tom Petty and the Heartbreakers, as the lead of his band, the Dirty Knobs. Newly minted TikTok sensation, Tommy Richmond. And two brothers, Jeff and Stephen McDonald, who've been leading the band Red Cross on and off for more than four decades.