For a rock star, Ty Segall may come across as surprisingly unassuming and demure – perhaps even quiet. Although the indie musician doesn’t make a habit of talking during his shows, that muted posture shifts when he steps onstage with his electric guitar and facilitates the kind of religious experience that can only come from basking in music that is really loud. And while he still relishes the enveloping power of blaring music as he gears up to release his latest album, “Three Bells,” on Friday, he concedes he has had to tone it down a bit in recent years.  (23 Jan.)