|City of license||Minneapolis, Minnesota|
|Broadcast area||Minneapolis-St. Paul|
|Branding||Classical Minnesota Public Radio|
99.5 HD-2 Classical 24
|First air date||1940 (AM), 1945 (FM)|
|Format||Public; Classical music|
|Callsign meaning||Variation of sister station KSJR-FM in St. Cloud|
|Former callsigns||WMIN-FM (1945-56)
|Owner||Minnesota Public Radio|
|Sister stations||KCMP, KNOW|
KSJN (99.5 FM) is the flagship station of Minnesota Public Radio's classical music network, serving the Twin Cities region. Prior to 1991, 99.5 was known as WLOL, best known as a top-rated CHR station during the 1980s.
KSJN intellectual unit 
Saint John's University in Collegeville, near St. Cloud, built and began operating the first station in the network, KSJR-FM (90.1 FM), in January 1967. By 1968, however, it was obvious that there weren't enough listeners in the immediate St. Cloud area for the station to be viable. KSJN nearly tripled its power in hopes of reaching the Twin Cities, but even then it only provided grade B coverage of Minneapolis and completely missed St. Paul. To solve this problem, St. John's signed on KSJN as a full-time repeater of KSJR-FM at 91.1 FM. By 1969, Saint John's realized it was in over its head operating a full-service radio station, so it turned over KSJR and KSJN to a nonprofit corporation, Saint John's University Broadcasting. This organization later changed its name to Minnesota Educational Radio, and finally Minnesota Public Radio.
In 1969 and 1970, MPR assisted in the formation of National Public Radio and was a founding member of the organization. Four years later, in 1974, the network began live broadcasting of Garrison Keillor's A Prairie Home Companion, one of the best-known programs on American public radio.
MPR made plans to establish a dedicated news/talk service as NPR's programming became more popular. To that end, in 1980, it purchased WLOL (1330 AM) and changed its calls to KSJN-AM. In 1989, the AM station changed its calls to KNOW, a callsign used by an AM station in Austin, Texas for 50 years. It began airing an expanded schedule of NPR programming, while the FM station continued to air a mix of NPR programming and classical music.
99.5 FM history 
The 99.5 frequency dates to 1945 when AM station WMIN started broadcasting on the new FM band. WMIN-FM was sold in 1956 to the owners of WLOL, becoming WLOL-FM, which remained until being sold to MPR in 1991.
The history of the WLOL call letters is intertwined with many other area stations. WLOL was first used in 1940 by 1300 AM and was a part of the Mutual Broadcasting System. The station moved up to 1330 in March, 1941 as required by the North American Radio Broadcasting Agreement (NARBA) under which most American, Canadian and Mexican AM radio stations changed frequencies.
For many years, WLOL-FM had a variety of formats. The original classical music format gave way to easy listening in 1973, then later soft rock as "FM100". The AM station was sold to MPR in 1980. The owner held on to WLOL-FM, and in 1981, the station dumped soft rock and became "Musicradio 99½ WLOL", the only Twin Cities FM station at the time playing Top 40 music. The new WLOL became a massive success, eventually achieving a 10-share in the Arbitron ratings.
The station was purchased by Emmis Broadcasting in 1983. New competition arrived later that year when longtime AM Top 40 station KDWB returned to their co-owned FM frequency after several years playing album oriented rock. WLOL and KDWB would go on to have a bitter rivalry throughout the 1980s, with WLOL dominating the format in the Twin Cities for the next five years.
By the late 1980s, the tables were turned. Some listeners felt WLOL had grown stale, while KDWB suddenly became the hip new CHR station. From that point on, KDWB jumped ahead of a slumping WLOL, and would, from that point on, be the dominant CHR station in the market. Playing catch-up, WLOL started tweaking the programming and airstaff, shook up its longtime morning show, and finally, in May 1990, teased a format change. Suddenly, on May 11, WLOL became a Rhythmic Top 40 station. Labeling themselves as "Today's Best Music", the new "99.5 WLOL" hired a new airstaff and rejuvenated themselves in the minds of many local listeners.
KSJN and KNOW relocation 
By 1990, Emmis Broadcasting fell on financially tough times due to their purchase of baseball's Seattle Mariners. They started selling off some of their most successful stations, including WFAN in New York and KXXX in San Francisco.
In 1991, Emmis found a buyer for WLOL. The shocking news was that the buyer was MPR, who desired to use it as the new location for KSJN while moving its NPR news and talk station, KNOW, from 1330 AM. After years of trying to purchase another FM station in the market, MPR agreed to buy the station for $12.5 million. This meant that WLOL would be no more. Pop music fans in the Twin Cities were furious as WLOL slowly counted down to their last day, February 26, 1991. WLOL signed off just after 6PM, and the next morning, 99.5 became the new home of KSJN, which began playing classical music 24 hours a day. The KNOW calls, along with all NPR news programming, moved to 91.1.
MPR had tried for more than a decade to buy a second FM frequency in the Twin Cities as part of its goal to offer dedicated news/talk and classical services across its network. The previous purchase of 1330 AM was a fallback plan for MPR, which had tried to buy KBEM-FM a year earlier to allow a split into two separate talk and classical music networks.
Technical aspects of 99.5 
In 1971, while it was WLOL-FM, the station participated in "quadcast" (quadraphonic stereo) experiments with an earlier incarnation of itself, when the KSJN call sign was used for 91.1 FM in the Twin Cities. In June 2005, KSJN became the first MPR station to broadcast regularly with the digital HD Radio system, and likely the fifth station in the state to use it. (KSJN currently features the Classical 24 feed on its HD2 subchannel.) The station's main transmitter is located on the KMSP-TV tower in Shoreview, Minnesota, with backup facilities atop the IDS Center in downtown Minneapolis.
A Prairie Home Companion 
Anyone seeing the live radio broadcasts at the Fitzgerald Theater, or those who saw the movie, A Prairie Home Companion (film), will recall a rare piece of radio studio hardware. Usually on the stage backdrop, a big round KSJN AM & FM clock graces the set.
- Founding Minnesota Public Radio — Saint John's of Collegeville
- Mark Durenberger (1999). Early quad-casts and other fun. The Broadcast Archive: War Stories.
- Julio Ojeda-Zapata (June 16, 2005). Digital revolution spreads to radio. Saint Paul Pioneer Press.
- Minnesota Public Radio
- MPR: KNOW 91.1/KSJN 99.5/KCMP 89.3 Minneapolis/St. Paul
- 99.5 WLOL-FM, primarily relating to the "Hitradio" format prior to KSJN
- 99½ WLOL Minneapolis/St. Paul tribute page
- A recollection by Jim Stokes, an announcer during WLOL-FM's classical music phase
- Query the FCC's FM station database for KSJN
- Radio-Locator information on KSJN
- Query Arbitron's FM station database for KSJN