Wet Leg are ready. The UK group, a recent-vintage Stereogum Band To Watch, is the buzziest buzz band to come along in quite some time. A few months ago, they made their American TV debut on Late Night With Seth Meyers, and they crushed it. That was one of those rare late-night TV performances that might actually have some impact on an artist’s career trajectory. Last night, Wet Leg once again paid a visit to 30 Rockefeller Plaza. This time, they hit a different studio, doing musical-guest duties on The Tonight Show.