Orthodontist's son grew up in Providence, R.I.; studied economics at Brown U. Moved to China for job with Boston chemical maker Wellman. Founded Providence Equity Partners 1989. Buys media and telecom companies, improves operations, sells for big profit. Biggest hit: invested $63 million in VoiceStream 1992; made more than $600 million when company was sold in 2000. First 4 funds returned between 21% and 111% a year. Now deploying $12 billion from firm's 6th fund. Last year paid $51 billion with Madison Dearborn, Ontario Teachers' Pension Plan for Bell Canada; largest buyout in history.