so I went to this tonight at the Orpheum in Los Angeles. Despite the misleading advertising, it is Jakob Dylan's band performing covers of 60s folk rock songs. Guest vocalists include Beck, Fiona Apple, Cat Power and Regina Spektor. In the performance I attended (the early one) Beck sang additional vocals on two songs that almost qualify as a duet, and participated inaudibly in one gang rendition of "Monday Monday" at the end. This is in news because they announced an album had been recorded. They also filmed the show with multi cameras. Hopefully both Beck tracks are on the album or to be released somehow.
Also I have an audience recording but not sure yet how this one turned out.