Four years ago, Cuban-born musician Hector Tellez Jr. was living in Havana: playing local clubs several nights a week, delivering passionate performances of well-oiled melodic blues rock. His style, merging the grit of Muddy Waters wailing on electric guitars with the tender-hearted yet mysterious air of Jeff Buckley, was not always welcomed by the locals, however. “In Cuba, it’s a Spanish language country, so I struggled a bit singing rock songs in English,” Tellez Jr. tells SPIN on a recent FaceTime video call from a friend’s backyard, looking every bit the brooding rocker, save for some frequent smiles. He’s wearing a cut-off muscle tee that shows off a few tattoos and a pair of round-rimmed sunglasses that look straight out of the John Lennon playbook. “There were a lot of naysayers, p...