Mos' new record uses his rock band, Black Jack Johnson, to interesting effect, but Sunday, Mos tried to carry the burden alone. On "The Panties," where Marvin Gaye is not-so-subtly sampled, Mos handled his moment of intimacy with a lover to dizzying effect. But his countless improvised, rambling excursions, during this song and throughout, made the night both excitingly spontaneous and, just as often, a tedious bore.