Waller Creek runs through downtown Austin, Texas, into Lady Bird Lake. It bustles with critters both furry and humanoid on a sunny day, but we took The Mynabirds' Laura Burhenn to the banks after midnight to sing us a lullaby. Looking like a mermaid with a Casio keyboard, she plays "All My Heart," a new song sure to be lushly arranged with a Motown beat on an album due out this summer, but here it's a lover's hymn: "I'd walk through hell for just one kiss / I'd give everything I have for a minute more of this."