Mustapha

Composer: Freddie Mercury
Meter: 4/4
Keys: f-minor, g#-minor, c#-minor, c-minor/g-minor, bb-minor
Form:  

  Intro I-II |
 | Verse  | Chorus |
 | Verse' | Chorus'|

Queen's "post-Races" period is considered to be less experimental than the period before (pre-News). Still we can find traces of new, up-to-date elements built into their music successively on each album up to Hot Space. The range of the length of the tracks (Jazz: 3:01-4:16 vs. Opera: 1:07-8:20) would make some people think that they started writing more "regular" songs. This is true, especially concerning the form. On the other hand, this album features a number of songs that are quite "progressive" in many subtle ways, even if they sound "normal" or "popular". This song with Arabic chants and scales, occassionally disorienting rhythm, and long circles of repetition is not a typical rock number; still, its relatively simple arrangement makes the track quite a listenable and easy to perform rock song.
The body of the song is built from two long cycles that consist of subsections. The major section-articulating device is the switching between mono and stereo mode, resulting in more than two minutes of the song (the Intro and the two Verses) being mono. Many of the subsections have AA-form and most of them are of "square" length. The step-wise ascending riffs with double notes, minor scales, off-beat, double phrases used throughout, and the "Arabic" ornaments are the piece's unifying elements.
In respect of harmony, the song presents something strange that makes it particularly hard to intrepret. What we've got is something very similar to modal inflection that textbooks apply for the major scale, but this case seems to go for minor scales. The chordal support often suggests another tonic that is the root of the actual scale used. How unusual it is you will know if you try to find anything like that (I couldn't...).
The song is shot through with many modulations and ephemeral keys with often minimal chordal support. The keys are all minor, mostly with "harmonic" inflection.

Walkthrough

Intro I
It's a stylized Arabic melody. Authentic Arabic music uses some slightly  off-key notes beside the "normal" ones known in European music. On stage Freddie would perfom this intro in a more "authentic" way. The melody, however, is a variant of what we can hear at 1:09. The pitch set is (D, Eb, F, G, Ab, Bb), and we have got a C in the variant subsection. This is the c-minor key. But toward the end of the intro the F is substituted by F#, which sounds like the sharp 7th degree of the G (harmonic) minor. The variant subsection also emphasizes the Gm chord as if it were the tonic (see below). If it is really g-minor, then it is (modally?) inflected with flat-2 degree (Ab).
The whole section is ad-lib performed, even though the variant subsection is rhythmically quantized. The Intro ends with a "hey!", which also closes the song. Except these two, you can collect four more "hey"-s in the song placed mostly off-beat, just like many of the cymbal hits provided by Roger.

Intro II
The seven measures of instrumental intro start right on downbeat, but this is not easy to figure out. The syllable "-pha" from "Mustapha" is on a first beat, too; that may help you pick up the beat. Disorienting factor is the off beat stops/accents applied at the end of the first and in the last measures and the way the downbeats get no extra emphasis; hence, once you loose the beat, it's very difficult to pick it up again.
The scalar (no chords played) piano part starts from g-minor, but in the second measure melodic f-minor scale is used, both natural and with flat seventh (Eb). The phrasing of the lead vocal is 2x2 AA', and the second phrase is repeated one octave higher. The guitar does not play until the first Chorus.

Verse
As it was mentioned, this is not a real a verse, but a chain of mini-sections. The first of these is a subsection, sort of mini-intro. It is 2x2 measures long:

f:
/--------2x-------\\
| Fm    | -  Eb/F |
| i     |     VII |

Next subsection is built from two four-measure phrases. The first phrase stays in f-minor. Let's take a look at the guitar fill that closes it in the second Verse: E, F, G, Ab, B, C, D, Eb, F... . The E is a sharp-7th, but we can find a curious flat-5th degree (B), too. The key shifts up to g#-minor for the second phrase. Note how Freddie uses "false" ornament/vibrato on the syllable "...him" from "Ibrahim". It's an arabic touch as Arabic music also uses some non-standard for Western-music note intervals.f: | Fm  | -  | -  | -  | | i   | -  | -  | -  | g# | G#m | -  | -  | B   | | i   | -  | -  | III |


Next sub-section starts with upbeat and is 2x2 measures long. First it seems to be in f#-minor, but in the second verse there is a guitar fill that uses the scale notes of the c#-harmonic-minor.

  |F#m | -  | -  | -  |
c#: iv | -  | -  | -  |
(f#:i)

The next four measures seem to use the G-harmonic minor scale, but (again) the tonic is not present. The phrasing is AA: 2x2 measures.

 | D  | -  | -  | -  |
g: v  | -  | -  | -  |

Freddie's voice is double-tracked: in the first phrase it's unisono; in the second phrase it's harmonized (paralell fifths). The instrumental backing is scalar. The sense of chords is created with the support of the lead vocal and the used scale.

The last subsection is a variant of Intro I. This is another double phrase: 2x4 measures long. The instrumental support is mostly scalar; the only full chord is the Gm. The key is either c-minor or modally inflected (G#=flat2) g-minor.

 /------------  2x  --------------\\
 | Gm  | F1  | Eb1 | C1 D1 Eb1 F1 |
g: i
c: v

In the first four measures Roger uses asymmetric emphasis (on the 1st and 4th eighth note) that becomes symmetric in the second phrase.

The second Verse is slightly different:
There are three-part harmonies (both guitar and vocal). There is a rhythm guitar and a solo guitar. Some of the rhythm guitar parts are double-tracked and octave-parallel. The guitar fill at 1:59 is very interesting: it starts in f-harmonic minor and modulates to c-harmonic minor. There is a general pause at the end of the section, but formally that measure belongs to the second Chorus.

Chorus
The first two measures feature the same scalar riff that started Intro 2  but in a shortened form. This means there's a modulation from Gm to f-minor. The sudden change to stereo has got a bombastic effect because the entering guitar makes the record louder. Similar trick is used in the intro of Dead On Time.

Next sub-section is square eight measures long and consists of four variant phrases. In the fifth measure there's a key shift up to g-minor. May we interpret these two phrases being in iflected bb-minor and c-minor keys? It's beyond me.

f:
| Bbm| -  | -  | -  |
| iv | -  | -  | -  |

g:
| Cm | -  | -  | -  |
| iv | -  | -  | -  |

The vocals are arranged antiphonally. In the next phrase there is a modulation similar to what we saw at the start of Intro II.

bb:
|  Ab | Bb1 C1 Db1 Eb1 | Dbm    | Bb1 C1 Db1 Eb1 | C1 D1 Eb1...
| VII |  i...          | flat-iv| i             c: i ...

The section is eight measures long but not in a predictable way. The rhythm is so disorienting that it's hard to keep the beat (just try it out!) due to some mini-upbeats on the 8th eighth. Similar gambit is used in Don't Stop Me Now from the same album, too. Last measure features three-part guitar harmonies gradually turning from stereo to mono.

The second Chorus starts with a general pause. Except the missing notes "erased" by the pause, the ascending riff is the same as in the first Chorus. The second subsection features the lead vocal and the guitar (with heavy vibrato) arranged antiphonally. Roger (?) uses hawk bell.