Hart, who wrote and produced for years with Tommy Boyce, died in his Los Angeles home after a period of poor health

Bobby Hart, a key part of the Monkees’ multimedia empire who teamed with Tommy Boyce on such hits as Last Train to Clarksville and (I’m Not Your) Steppin’ Stone, has died. He was 86.

Hart died at his home in Los Angeles, according to his friend and co-author Glenn Ballantyne. He had been in poor health since breaking his hip last year.

Boyce and Hart were a prolific and successful team in the mid-1960s, especially for the Monkees, the made-for-television group promoted by Don Kirshner. They wrote the Monkees’ theme song, with its opening shot, “Here we come, walkin’ down the street,” and enduring chant, “Hey, hey, we’re the Monkees,” and their first No 1 hit, Last Train to Clarksville. The Monkees’ eponymous, million-selling debut album included six songs from Boyce and Hart, who also served as producers and used their own backing musicians, the Candy Store Prophets, as session players.

“I always credit them not only with writing many of our biggest hits, but, as producers, being instrumental in creating the unique Monkee sound we all know and love,” the Monkees’ Micky Dolenz wrote in a foreword to Hart’s memoir, Psychedelic Bubble Gum, published in 2015.