When you’re pianist/composer Gregg Kallor, instead of celebrating Halloween with a $5 mask and one too many Kit Kats, you give the world premiere of your new musical rendition of Edgar Allan Poe’s The Tell-tale Heart for piano and mezzo-soprano-slash-rockstar Elizabeth Pojanowski. A collaboration with On Site Opera, the The Tell-tale Heart features a semi-staging setup by the always-awesome director Sarah Meyers, whom you might know from a little place called The Metropolitan f-ing Opera. Oh, and if you’re Gregg then you also perform your cello sonata, Undercurrent, as well with cello superstar Joshua Roman, just for good measure.