WEBH was broadcasting on 93.9 FM since 1958. WEBH changed to WWEL sometime in 1970. The station broadcast "beautiful music", an easy listening format with mostly instrumentals and a couple of soft vocal songs per hour. WWEL was "Well" from mid-1970-1972, to describe the easy listening format that was broadcast on 93.9 FM. It was also that way long before. WWEL changed call letters to WLAK in 1972. At that time Viacom bought WLAK. WLAK continued to play mostly instrumental easy listening but increased vocals to about four an hour. In 1983 WLAK switched to Soft AC playing 99% vocal songs and virtually no instrumentals. Core artists were Neil Diamond, Barbra Streisand and others. WLAK was very successful in the format, actually one of the first in the nation preceding its sister station WLTW in New York. WLAK changed call letters in 1989 to WLIT, as Lite FM. WLIT has continued to broadcast in the Chicago area since then. In the mid-1990s, WLIT evolved out of Soft AC and into a straight AC format. Viacom sold their radio stations to Chancellor in 1997, making WLIT a Chancellor station. Chancellor restructured and became known as AMFM Inc. in 1999. In 2000, WLIT fell under the ownership of Clear Channel Communications after Clear Channel's merger with AMFM. In February 2006, WLIT began broadcasting in HD Radio. WLIT's HD-2 was originally a simulcast of the now-defunct "Real Oldies" WRLL (now WVON) 1690 AM, then changed to a mix of disco music and 1970s/1980s called "Flashback." In August 2009, the format changed again, this time to a gold-based AC format branded as "Chicago's Classic Lite." From November through Christmas Day each year, WLIT changes its branding to The Holiday Lite and format to continuous Christmas music, resuming its regular branding and format on December 26. During the period between December 26 and January 2, the Christmas music moves to the HD2 channel while the main terrestrial station resumes the regular format. WLIT became Chicago's only adult contemporary station on August 1, 2011, when former rival WCFS-FM flipped to a simulcast of WBBM-AM. This marks it the first time in years Chicago has had only one adult contemporary radio station.

City of license	Chicago, Illinois
Broadcast area	Chicagoland
Branding	93-9 Lite FM
Frequency	93.9 MHz
First air date	April 7, 1958 (as WEBH)
Format	HD1: Adult contemporary HD2: "Chicago's Classic Lite" (gold-based AC)
ERP	4,000 watts
HAAT	482 meters
Class	B
Facility ID	70042
Callsign meaning	LITe FM
Former callsigns	WEBH (1958-1970) WWEL (1970-1972) WLAK (1972-1989)
Owner	Clear Channel Communications (AMFM BROADCASTING LICENSES, LLC)
Sister stations	WGCI-FM, WGRB, WKSC-FM, WNUA, WVAZ, WVON
Webcast	Listen Live
Website	http://www.litefm.com

Source :http://en.wikipedia.org/wiki/WLIT-FM