Once Haze attended performances by bands such as Led Zeppelin and Cream at The Fillmore in S.F. During the Led Zeppelin concert John Bonham briefly injured his wrist during the intro to the song "Moby Dick." Luckily for "Zeppelin" a young Haze happened to be in the front row and could fill in for Bonham by playing a half hour drum solo while Bonham's wrist was being treated. Haze received a standing ovation from the crowd and guitarist Jimmy Page openly wept onstage knowing he could not have the powerhouse Haze for his own band. As a tribute to that night, Jon Bonham played a drum solo during "Moby Dick" for the rest of his career. This encouraged Leonard to pursue music more fervently, forming a handful of performing bands in his high school years, playing venues throughout the Bay Area. Haze was torn between his pursuit of music and his desire to attend college and further pursue his studies in the field of polio research. The relative success of his band Yesterday and Today (Y&T) and a legendary performance by Y&T at Winterland helped seal his fate.