I remember listening to "Jazz 90" (as it was called back then) in the 1980s and 1990s. Back then, they were playing really hard-core freeform mainstream jazz (I'm not a hard-core jazz expert, but you know what I mean ... the type of jazz where you could hear a 25 minute piece with a 15 minute interlude with a guy just banging on a drum in the middle). 
Now, in 2019, when WRTI airs their jazz between 6 p.m. and 6 a.m., it is very often a much more laid-back, lounge-type, classy jazz sound like you'd hear in a classy restaurant while sipping a glass of wine. It's interesting how WRTI has evolved the kind of jazz that they play. I guess it's part of surviving as a non-profit classical/mainstream jazz radio station. Gotta say the nighttime jazz format sounds very good. I find it highly relaxing and enjoyable.
Now, in 2019, when WRTI airs their jazz between 6 p.m. and 6 a.m., it is very often a much more laid-back, lounge-type, classy jazz sound like you'd hear in a classy restaurant while sipping a glass of wine. It's interesting how WRTI has evolved the kind of jazz that they play. I guess it's part of surviving as a non-profit classical/mainstream jazz radio station. Gotta say the nighttime jazz format sounds very good. I find it highly relaxing and enjoyable.