It's the 1950s, and after taking LSD for the first time, the movie legend and one-time vaudevillian is getting psychically re-acquainted with his much younger self through song and tap dance. The tune is impressively catchy, and the routine, as choreographed by Michelle Dorrance and executed by Yazbeck and Ware, is so exhilarating that you may feel chemically enhanced just watching it. I'd love to report that Sunset sustains that high for its roughly two and a half hours, but this long, strange trip-featuring a book by James Lapine, who also directs, music by Tom Kitt and lyrics by Michael Korie-is ultimately an uneven one.