In vocal jazz, scat singing is vocal improvisation with random vocables and syllables or without words at all. Scat singing gives singers the ability to sing improvised melodies and rhythms, to create the equivalent of an instrumental solo using their voice.
The deliberate choice of scat syllables also is a key element in vocal jazz improvisation. Syllable choice influences the pitch articulation, coloration, and resonance of the performance. Syllable choice also differentiated jazz singers' personal styles: Betty Carter was inclined to use sounds like "louie-ooie-la-la-la" (soft-tongued sounds or liquids) while Sarah Vaughan would prefer "shoo-doo-shoo-bee-ooo-bee" (fricatives, stop consonants, and open vowels). The choice of scat syllables can also be used to reflect the sounds of different instruments. The comparison of the scatting styles of Ella Fitzgerald and Sarah Vaughan reveals that Fitzgerald’s improvisation mimics the sounds of swing-era big bands with which she performed, while Vaughan’s mimics that of her accompanying bop-era small combos.
Another method of scat singing is practiced by guitarists who scat along with their solos note for note. Notable practitioners include George Benson, Sheldon Reynolds, Rik Emmett, Prince, Jason Mraz and Jack Black.
Jelly Roll Morton credited Joe Sims of Vicksburg, Mississippi as the creator of scat around the turn of the 20th century. Here is a transcription of a conversation between Alan Lomax and Jelly Roll Morton where Morton explains the history of scat :
Lomax: Well, what about some more scat songs, that you used to sing way back then?Morton: Oh, I'll sing you some scat songs. That was way before Louie Armstrong's time. By the way, scat is something that a lot of people don't understand, and they begin to believe that the first scat numbers was ever done, was done by one of my hometown boys, Louie Armstrong. But I must take the credit away, since I know better. The first man that ever did a scat number in history of this country was a man from Vicksburg, Mississippi, by the name of Joe Sims, an old comedian. And from that, Tony Jackson and myself, and several more grabbed it in New Orleans. And found it was pretty good for an introduction of a song.Lomax: What does scat mean?Morton: Scat doesn't mean anything but just something to give a song a flavor. For an instance we'll say: [launches into an example scat song, accompanying himself on the piano]
Morton also once boasted, "Tony Jackson and myself were using scat for novelty back in 1906 and 1907 when Louis Armstrong was still in the orphan’s home." Don Redman and Fletcher Henderson also featured scat vocals in their recording of "My Papa Doesn’t Two-Time No Time" five months prior to Armstrong’s 1926 recording of "Heebie Jeebies."
Scat singing could be considered by some authorities as not respectable. It was for example not allowed on BBC radio in the late thirties, before the second world war.
Over the years, as jazz music developed and grew in complexity, scat singing did as well. During the bop era, more highly-developed vocal improvisation surged in popularity. Annie Ross, a bop singer, expressed a common sentiment among vocalists at the time: "The [scat] music was so exciting, everyone wanted to do it." And just about everyone did: Ella Fitzgerald, Eddie Jefferson, Betty Carter, Anita O’Day, Joe Carroll, Sarah Vaughan, Carmen McRae, Jon Hendricks, Babs Gonzales, and Dizzy Gillespie all were important singers in the idiom. Fitzgerald once hailed herself as the “best vocal improviser jazz has ever had,” and critics since then have been in almost universal agreement with her. In the 1960s, traditional scatting gave way to the free-jazz movement, which allowed scat singers to include sounds in their repertoire that had before been considered non-musical, such as screams, cries, and laughter. Free jazz and the influence of world musicians on the medium pushed jazz singing nearer to avant-garde art music. The bop revival of the 1970s renewed interest in bop scat singing, and young scat singers viewed themselves as a continuation of the classic bop tradition. The medium continues to evolve, and vocal improvisation now often develops independently of changes in instrumental jazz.
Protopunk band The Stooges songs would often descend into scat singing at the end or midway through track in their albums Raw Power and Fun House with the lead singer Iggy Pop spouting strange vocal imporovisations and screams.
Jazz artist Scatman John renewed interest in the genre briefly during the mid-90s. This has continued to a degree in recent years, following popular television series The Mighty Boosh's use of scat singing as a recurring theme, along with the scat-related singing style of crimping.
Dave Matthews, frontman of Dave Matthews Band, is also a noted enthusiast of vocal scating, often employing it into songs during live performances. During periods of improvisation, Matthews will begin to utter jittery, nonsensical phrasings as well as more traditional forms of scat in combination. Fans often refer to Matthews' ecclectic style as "Davespeak", and techniques similar to his are used by other associated acts such as O.A.R. and moe..
Vocal improviser Bobby McFerrin’s recent performances have shown that “wordless singing has traveled far from the concepts demonstrated by Louis Armstrong, Gladys Bentley, Cab Calloway, Anita O’Day, and Leo Watson”.
Some writers have proposed that scat has its roots in African musical traditions. In much African music, "human voice and instruments assume a kind of musical parity" and are "at times so close in timbre and so inextricably interwoven within the music’s fabric as to be nearly indistinguishable." Dick Higgins likewise attributes scat singing to traditions of sound poetry in African-American music. In West African music, it is typical to convert drum rhythms into vocal melodies; common rhythmic patterns are assigned specific syllabic translations. However, this theory fails to account for the existence—even in the earliest recorded examples of scatting—of free improvisation by the vocalist. It is therefore more likely that scat singing evolved independently in the United States.
Others have proposed that scat singing arose from jazz musicians' practice of formulating riffs vocally before performing them instrumentally. (The adage "If you can’t sing it, you can’t play it" was common in the early New Orleans jazz scene.) In this manner, soloists like Louis Armstrong became able to double as vocalists, switching effortlessly between instrumental solos and scatting.
Scat singing can allow jazz singers to have the same improvisational opportunities as jazz instrumentalists: scatting can be rhythmically and harmonically improvisational without concern about destroying the lyric. Especially when bebop was developing, singers found scat to be the best way to adequately engage in the performance of jazz.
Scatting may be desirable because it does not "taint the music with the impurity of denotation". Instead of conveying linguistic content and pointing to something outside itself, scat music—like instrumental music—is self-referential and "d[oes] what it mean[s]. Through this wordlessness, commentators have written, scat singing can describe matters beyond words. Music critic Will Friedwald has written that Louis Armstrong's scatting, for example, "has tapped into his own core of emotion," releasing emotions "so deep, so real" that they are unspeakable; his words "bypass our ears and our brains and go directly for our hearts and souls".
Various psychological and metaphysical theorists have instead proposed that vocal improvisation allows for revelations from the soul’s depths. Musician and lecturer Roberto Laneri has proposed a theory of improvisation based on "different states of consciousness" that draws on the Jungian model of the collective unconscious. The music stemming from Laneri’s improvisatory "consciousness expansion" tends to be vocal, as the voice is regarded as the "primal instrument".
Scat singing has never been universally accepted, even by jazz enthusiasts. Writer and critic Leonard Feather offers an extreme view: he once said that "scat singing—with only a couple exceptions—should be banned." Many of the finest jazz singers, including Bessie Smith, Billie Holiday, Jimmy Rushing, and Dinah Washington, have avoided scat entirely. Jazz singers Sarah Vaughan, Betty Carter, and Anita O’Day are at times cited as examples of vocalists who should have avoided scat singing.