Each year at SXSW, a few emerging artists become the talk of the festival. This year, Cautious Clay — the far-reaching and breezily soulful project of singer and multi-instrumentalist Josh Karpeh — appears to be one of the names on attendees' lips. As luck would have it, Karpeh appeared at NPR Music's Tiny Desk Family Hour on Tuesday night, and this was the way to witness the band do its work: before a reverent crowd, in a reverent setting, with impeccable sound to bring out the richness and depth in Karpeh's voice. Cautious Clay performed five songs at Austin's Central Presbyterian Church, one of SXSW's best settings.