"Rhoads and Osbourne's 'Mr. Crowley' (1981) also begins with synthesised organ, playing a cyclical harmonic progression modelled on Vivaldi. The minor mode, the ominous organ and the fateful cyclicism, culminating in a suspension, set up an affect of mystery and doom. The sung verses and first guitar solo of 'Mr. Crowley' are supported by a metal-inflected Baroque harmonic progression: Dm | Bb | C | Dm B Bb | Em7b5 I Asus4 | A. The move from Bb back up through C (bVI-bVII-I) is uncharacteristic of Baroque music (where bVI usually resolves to V), but it frequently occurs in metal, where it normally functions in an aggressive and dark Aeolian mood.
The progression that underpins Rhoads' 'outro' (the opposite of 'intro') solo at the end of the song is similar, but it is a more straightforward Vivaldian circle of fifths progression: Dm I Gm7 C I F | Bb | Em7b5 | ASUS4 | A. Until classically-influenced heavy metal, such cyclical progressions were very unusual in rock and soul music, which had been fundamentally blues-based.
The classical influence contributed to a greater reliance on the power of harmonic progression to organise desire and narrative, as well as the turn towards virtuosic soloing. The circle of fifths progression was picked up by metal because it sounds archaic, directional and thus fateful. Rhoads' first solo in 'Mr. Crowley' is a frantic scramble against the inevitability of the harmonic pattern. The second rides the wave of harmonic teleology with more virtuosic aplomb (see Example

Rhoads displays similar technical devices on a live recording of 'Suicide Solution' (released in 1987), during the course of a lengthy virtuosic cadenza. The crowd's reactions are clearly audible as counterpoint to Rhoads' phrases, confirming that the purpose of virtuosic technique is to facilitate fantastic rhetoric; the virtuoso strives to manipulate the audience by means of skilful deployment of shared musical codes of signification.
In the seventeenth and early eighteenth centuries, music was theorised in these terms very openly, in treatises on the Affektenlehre, before the rise of aesthetics led to circumlocutions and mystifications of music's power. Moreover, contemporary accounts show that until late in the nineteenth century, the behaviour of concert audiences was far from today's 'classical' norms of silence and passivity. Musical audiences were 'tamed' around the turn of this century, as part of the cultural segregation of private emotions and public behaviour so well analysed by Lawrence W. Levine.
Until the twentieth century, it seems that large audiences for opera and public concerts behaved very much like today's audiences for heavy metal and other popular music. Listeners reacted to musical rhetoric with 'spontaneous expressions of pleasure and disap- proval in the form of cheers, yells, gesticulations, hisses, boos, stamping of feet, whistling, crying for encores, and applause' (Levine 1988, p. 192). In the studio recording of 'Suicide Solution', which appeared on Blizzard of Ozz (1981), there is no guitar solo at all, an unusual departure from the formal norms of heavy metal, but an appropriate one, given the song's musical delineation of powerlessness.
But in concert, Osbourne used the song as an opportunity for Rhoads to display his prowess as a soloist. Where the song would normally end, it is suspended inconclusively instead, and Rhoads begins a virtuosic cadenza made up of carefully paced statements and flourishes, divided by charged gaps which seem to demand replies from the audience (see Example 9). Rhoads uses speedy patterns and fast runs to build excitement, and he manages the rhythmic impulses of his lines so as to create and then suspend metric expectations. Tried and true harmonic devices, such as diminished arpeggios and chromatic 'melt- downs', are borrowed from classical musical semiotics in order to manipulate desire, by suggesting, deflecting, achieving or making ambiguous a variety of tonal goals."
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The article also included tabs for the Mr. Crowley solos as well as his spotlight solo, all taken from the Wolf Marshall book. If anyone is interested, the article is in Popular Music, Volume 11 Number 3.