While they were unquestionably kindred spirits, Tom Petty and Bruce Springsteen never really collaborated, apart from sharing stages at events like the 1979 “No Nukes” concert, a 1986 Bridge benefit and, wow, that 1990 show in L.A. when Springsteen and Bob Dylan joined Petty onstage for an encore. The reasons for that are fairly obvious: Their musical styles and lyrical subject matter are quite similar, they’re both alpha bosses, and they’re both such strong and distinctive songwriters that there arguably wasn’t much room — or need — for the other in a song.

Yet theirs was a friendship that stretched back to the 1970s — Petty considered the Boss a “fellow traveller,” according to Warren Zanes’ excellent 2015 biography — and on the morning of Springsteen’s first preview of his four-month run of solo shows on Broadway, he posted a tribute to his colleague, who died late Monday after suffering a cardiac arrest on Sunday.

“Down here on E Street, we’re devastated and heartbroken over the death of Tom Petty. Our hearts go out to his family and bandmates,” he wrote. “I’ve always felt a deep kinship with his music. A great songwriter and performer, whenever we saw each other… …it was like running into a long lost brother. Our world will be a sadder place without him.”

Springsteen fans will not want to miss Variety‘s two-part interview with the Boss, which published this morning.