Origins The classic hip-hop format dates back to 2004, when KZAB, a Spanish-language FM station serving the Los Angeles area, was re-launched as
KDAY. The re-launched station served to capitalize on the heritage of the original KDAY on the AM dial (now
KBLA), which in the 1980s was the first radio station in the United States to play hip-hop music on a full-time basis. After the station's sale to
Fred Sands in 1991, the station dropped hip-hop and switched to business news. The new KDAY originally focused primarily on classic hip-hop music: over the following years, it backtracked on its gold-based format, before reinstating it in 2009. The station's initial success was hampered primarily by its signal, which did not cover all of
Greater Los Angeles (a rebroadcaster,
KDEY-FM, was also established to improve the station's reach in the
Inland Empire), along with the music itself, as hip-hop music from the 1990s was not yet nostalgic to listeners. Listenership of the new format saw a dramatic improvement over its previous all-news format: the following month, KROI improved its
audience share of 0.9, 26th place among Houston stations, to 3.2, 14th place in the market. In response to its success, Radio One began to flip further stations to the Boom format and brand, including Philadelphia's
WPHI-FM and Dallas's
KSOC. At the same time, other station groups, including
iHeartMedia,
Cumulus Media,
Univision Radio, and
Cox Media Group, began to slowly introduce classic hip-hop formats of their own. In November 2014,
WTZA became the first station in the
Atlanta market to adopt classic hip-hop; a few days later, both Cumulus Media's
W250BC and Radio One's
W275BK flipped as well, with the latter using the Boom branding. Some stations, over the 2014 holiday season, shifted towards classic hip-hop as a temporary format. KROI's success was short-lived; by December 2016, it had fallen back towards a 1.4 share. In January 2017, KROI would drop its classic hip-hop format in favor of
contemporary hit radio. == List of stations airing the format ==