Mezzo-soprano Hilerie Klein-Rensi and pianist Pej Reitz combined forces to present their fourth staging of "Alto on the Loose" Sunday (Dec. 5) at the Schorr Family Firehouse Stage. Klein-Rensi sang more than 20 show tunes -- some silly, some serious, some sublime -- all to illustrate the point that, while sopranos are the darlings of song, altos often portray more interesting, complex roles in musical theater. Reitz accompanied with her usual exuberance and intensity.