Ever since classical music station WFLN switched to a rock format in the mid-1990s, fans of classical music and jazz in the city of Philadelphia have had to share a single radio station, Temple University-owned WRTI, which attempts to please everyone with 12 hours of classical and 12 hours of jazz each day. It’s better than nothing, of course, but there’s been plenty of grumbling about the lack of seperate jazz and classical stations in the nation’s 4th-largest radio market. But now, WRTI is planning to begin splitting its signal into two different full-time streams – one jazz, one classical – offering listeners with high-definition receivers a choice of what they hear at any given time.