world renowned organist stephen tharp was rehearsing for the and a girl concert on an instrument thatd to better command its space to flood this nontraditional sanctuary. >> it is kind of a surprise for people who perhaps never heard an organ recital and wonder where all the sound and color is coming from because you cannot see it. as to what you are going to hear is behind this red scream. >> i got a chance to peek behind the screen thanks to casey. all of his older stuff below the level of the second floor up there is the original organ. a st. john's graduate and organ builder himself he has maintained this one for 45 years. >> so what we ended up doing was preserving the old instrument and building upon it. the new organ gives at the extra power it needed. >> many instruments use mechanical pumps to send air through the pipes at this one uses electronic signals. to tune it he uses a phone app. >> on the control side of things we are up currently with the technology on the sound side of things we are back centuries. >> the pipe organ dates back to ancient greece and its industrial s