In 1998, Congress answered "Yes." A webcaster owes both. How much is owed to the record companies? Whatever they want to charge, if they want to allow the webcast at all. Unless, of course, a webcaster qualifies for a compulsory license by—and this is in the law—transmitting during any given three-hour period no more than any of (1) three different selections of sound recordings from any one CD, if no more than two such selections are transmitted consecutively, and (2) four different selections of sound recordings by the same featured recording artist or from any set or compilation of CDs distributed together, if no more than three such selections are transmitted consecutively. Got that? Oh, and the webcaster must take care not to preannounce what songs are about to be played. Hew to all these rules, and you still pay—it's just that the rate, rather than being set by the record company, is set under the law by a three-judge arbitration panel after taking weeks of testimony, as long as the panel is not overruled (as really happened) by a subsequent act of Congress setting entirely different rates.
Source:
The Copyright Cage