Have you ever been singing in your shower and, impressed with your own voice, wished you could record it then and there so that the world could bask in your magnificent vocal abilities? On their debut, Acoustic Session, the duo of Sean Lennon (yes, that Sean Lennon) and Charlotte Kemp Muhl, collectively known as Ghost Of A Saber Tooth Tiger, did just that, recording the entire piece in their house. Now the duo is coming to Rockwood Music Hall on Saturday Jan. 8 to pull back the shower curtain and invite listeners to hear the sounds they created.