their stage appearance with trendy suits and wide audience appeal and were known for their signature song, "Happy Rhythm" (Rockin and a'Rollin). Gaither Homecoming series Traditional southern gospel music underwent a tremendous surge in popularity during the 1990s thanks to the efforts of Bill and Gloria Gaither and their Gaither Homecoming tours and videos, which began as a reunion of many of the best known and loved SGM individuals in 1991. Thanks in part to the Homecoming series, southern gospel music now has fans across the United States and in a number of foreign countries like Ireland and Australia. 1990s and beyond By the 1990s, the "old-timey" quartet-style music began to develop to include more soloists and duos. Although still mostly popular in the Southeast and Southwest, it has a nationwide and even international audience. The music remains "more country than city, more down-home than pretentious". In 2005, The Radio Book, a broadcast yearbook published by M Street Publications, reported 285 radio stations in the U.S. with a primary format designation as "southern gospel," including 175 AM stations and 110 FM stations. In fact, southern gospel was the 9th most popular format for AM stations and the 21st most popular for FM. Southern gospel radio promoters routinely service more than a thousand radio stations which play at least some southern gospel music each week. Recent years have also seen the advent of a number of internet-only southern gospel "radio" stations. Two popular satellite stations that feature southern gospel are channel 34 on XM Satellite Radio and Channel 65 (changed from 67). On Sirius Satellite Radio. Both play the same feed entitled, "enLighten on SiriusXm". Enlighten plays southern gospel and has several featured programs which air weekly including Paul Heil's Gospel Greats and Bill Gaither's Homecoming Radio. Over the last decades, a newer version of southern gospel has grown in popularity. This style is called progressive southern gospel and is characterized by a blend of traditional southern gospel, bluegrass, modern country, contemporary Christian and pop music elements. Progressive southern gospel generally features artists who push their voices to produce a sound with an edge to it. The traditional style southern gospel singers employ a more classical singing style. Lyrically, most progressive southern gospel songs are patterned after traditional southern gospel in that they maintain a clear evangelistic and/or testimonial slant. Southern gospel purists view lyrical content and the underlying musical style