Maybe you first tune in the station driving past some lobster-roll shack just outside Bangor, Maine. You know the music isn't coming from the local FM radio tower a few miles away. Instead, it's being digitally compressed and uplinked from a massive command center in Washington, D.C., bouncing off a pair of Boeing satellites in geostationary orbit high above the equator, and finding its way to a sleek little shark-fin antenna mounted on the trunk. The technology is at best a compelling afterthought, because after the fourth or fifth song, you realize the music speaks to you. It's the kind of expressive jazz or reggae or alternative country you thought nobody played on the radio, except for some underpowered college station whose signal turns into a death rattle before Coltrane takes his first solo. But this signal does not fade. It stays with you driving through lower New England and the muscular outer arteries of New York City, down past the Delaware Water Gap and across the Mason-Dixon line. One station, playing deep cuts from your favorite artists, introducing you to new, like-minded performers, and treating you not like a marketing demographic but like a music lover.