FALLS CHURCH resident musician and musical archivist Alex Hassan (right) and two colleagues he has worked with for a number of years, tenor Doug Bowles and soprano Kari Paludan, combined as “Three for a Song,” delighted full-house audiences at the Art Space of Falls Church earlier this month to kick off the Creative Cauldron’s summer Cabaret Series that runs every weekend through Sept. 26. The trio provided two performances of “a scandalous evening of sinfully good Broadway tunes” from the 20s and 30s. This weekend, the Cabaret Series continuess with two nights of “Bayla sings Barbra.”