Mike Morasky is one of Valve’s sound designers and composers. He’s been at the company since 2005, if not earlier. He’s done work for Day of Defeat: Source, Team Fortress 2, Portal, Portal 2, and the Left 4 Dead series.
He’s been instrumental (No pun intended, that’s what the press release actually said. I wouldn’t lie about that, because it’s a pretty great pun. If I was to actually lie about it, I would pretend I came up with it. Great pun.) in developing Portal 2’s brand new dynamic music system, as well as its entire soundscape and soundtrack.