There may have been no more voluble and volatile presence on the Boston rock scene in the late 1970s and 1980s than Jeff Conolly. The talented and temperamental Lyres singer and bandleader died Friday, July 31, after a bout with bladder cancer. “Jeff had his own language,” recalled Lilli Dennison, who booked Lyres numerous times into the club she booked, the Rat. While I was covering a gig in 1986 — with Lyres ostensibly promoting a new album, “Lyres, Lyres” — Conolly was backstage, post-show, waving a bottle of wine, veering between flip and self-flagellating: “This album is dead. Conolly and his Lyres carved out an important niche for themselves in a town full of young art-rock/post-punk bands and roots-rock bands.