With a voice like an angel -- and a devilish wit

With a voice of remarkable character and songs noteworthy for their emotional resonance, Sia captivated an enthusiastic crowd at the Troubadour on Monday. Yet throughout the hourlong set, there was an odd tinge of disappointment every time the Australian singer and her band began a song and a curious sense of pleasure every time they finished one.

That’s no knock on the performances, but Sia (full name: Sia Kate Isobell Furler) is just irresistibly funny and unpredictable between songs. It made for an odd split of sublime and silly, the tempered music versus her say-anything chatter. The latter peaked -- or bottomed -- Monday (the second of two Troubadour nights) when she revealed decidedly obscene nicknames for her band-mates and herself, all the more startling for the girlish veneer of her manner.

Of course, her singing voice alone is entrancing -- a sturdy yet vulnerable instrument that almost defies comparisons, as solidly earthy as Chrissie Hynde’s (evoked with “I Go to Sleep,” a Ray Davies ballad that Hynde did with the Pretenders), as breathily coquettish as Norah Jones’, capable of both Shirley Bassey-like growls and diva-ready R&B; runs.

Used to full effect in recordings with English semi-electronic duo Zero 7 and on numbers of her own such as “Breathe Me,” showcased last year behind the final sequence of “Six Feet Under,” it’s understandably made her a favorite of KCRW-FM (89.9) sophisticates and a mainstream KROQ-FM (106.7) audience.

Over the course of a whole set, more freewheeling variety in the music would have been good -- perhaps some real jazz flights (hinted at near evening’s end in “Distractions”) or even something Sondheim-ish. She’s still early in her career, though, and there’s plenty of time to show more range, both as a singer and a talker.