A pianist was hired to play background music for a movie. When it was completed he asked when and where he could see the picture. The producer sheepishly confessed that it was actually a porno film and it was due out in a month.A month later, the musician went to a porno theatre to see it. With his collar up and dark glasses on, he took a seat in the back row, next to a couple whom also seemed to be in disguise.The movie was even raunchier than he had feared, featuring group sex, S/M and even a dog.After a while, the embarrassed pianist turned to the couple and said, "I'm only here to listen to the music.""Yeah?" replied the man. "We're only here to see our dog."