By Steven Mirkin
Updated May 19, 1995 at 04:00 AM EDT

On about one third of the 32-minute You Must Ask the Heart, Jonathan Richman taps into the tuneful simplicity of doo-wop. But the rest of the time, his attempts at childish whimsy sound forced, and emotional complexities seem beyond his reach, making this monotonous and insubstantial. C-