Incredible sex - so incredible that you hear a complete symphony in your head, reaching their climactic point as you do, and ending with wild applause. Can cause individuals involved in symphony sex to attempt to scream or sing out along with the music.
As he rocked back on his hips, driving himself further into me, I heard, even though it was only the two of us in the room and both the TV and radio were off, an entire string section of an orchestra build. As his speed increased the woodwinds entered. By the time I was about to cum the entire orchestra was crescendoing, drums were pounding, strings singing at full forte, all at a fevered pitch until, in unison with me, everything peaked and held for a seemingly impossible note - all followed by wild applause and exhaustion. He collapsed next to me and I screamed "ENCORE! More Symphony Sex! ENCORE!", but alas, he was already asleep.
The band symphony X is concidered so increadibly sexy by people with small penises, that they had to describe it with sex and not X.
Symphony sex is sex to my ears