Country music is primarily a fusion of African American blues and spirituals with Appalachian folk music, adapted for pop audiences and popularized beginning in the 1920s. Of particular importance was Irish and Scottish tunes, dance music, balladry and vocal styles, as well as Native American, Spanish, German, French and Mexican music. The instrumentation of early country revolved around the European-derived fiddle and the African-derived banjo, with the guitar added later. Country music instrumentation used African elements like a call-and-response format, improvised music and syncopated rhythms. Later still, string instruments like the ukulele and steel guitar became commonplace due to the popularity of Hawaiian music in the early 20th century and the influence of musicians such as Sol Hoʻopiʻi and Lani McIntyre. The roots of modern country music are generally traced to 1927, when music talent scout Ralph Peer recorded Jimmie Rodgers and The Carter Family. Their recordings are considered the foundation for modern country music. There had been popular music prior to 1927 that could be considered country, but, as Ace Collins points out, these recordings had "only marginal and very inconsistent" effects on the national music markets, and were only superficially similar to what was then known as "hillbilly music". In addition to Rodgers and the Carters, a musician named Bob Wills was an influential early performer known for a style called Western swing, which was very popular in the 1920s and 30s, and was responsible for bringing a prominent jazz influence to country music.