I have also heard on 93.7, the oldies, Rush, alternative music and jazz. Over in the Summerlin area around Hwy 95, there was a female announcer saying "Jazzy 93.7". Around Serene/Eastern and Hwy 215, where Walmart, Home Depot, In And Out Burger are, alternative music is playing constantly. However, it is a low powered transmitter and disappears about a mile up/down Eastern Avenue in both directions. There is no identification, it almost sounds like music for a restaurant. Finally, out in Henderson, up Anthem Parkway near Hampton, I have heard conversation, from a Talk station with Rush Limbaugh in the late afternoon. All of these stations fade in and out as you drive by the various areas. The two in Henderson are usually very strong in the areas I have described. I have assigned a push button to 93.7 to check in from time to time. My guess is low powered transmitters being used.
Perhaps also, it could be a "skip" of a distant FM signal, due to the towering clouds in our area or in another state to the east of Nevada, even in the midwest. The FM signals come in like a local station from an area 200-300 miles away. About two weeks ago, I listened to a FM Country Station that was broadcasting on 93.7 from Salina, Kansas. It faded in and out with other stations in the background for a period of about 45 minutes. You can read more about "Dx'ing" on the radio on the Radio Info site, scroll down the list.