Keep Passing The Open Windows

Composer: Freddie Mercury
Meter: 4/4
Key: C-Major
Form:

        | pre-chorus - instr. Chorus ||
               Verse - Chorus ||
             | Verse - Chorus ||
        | pre-chorus - Chorus |
  | Solo (pre-chorus)- instr. Chorus' |
        | pre-chorus"- Chorus - tag (8x) fade out

This is a relatively straightforward song, a combination of rock n roll and ... and something hard to pigeonhole. The form shows six cycles (including an instrumental one) closing each with a Chorus. We surely take it granted the many developments on the sections cycle-by-cycle.
The key choice and the chords progressions are relatively straithforward, we have two borrowed chords: bVII and v.

Pre-chorus
This section is not a textbook-like "lift-up" pre-chorus but other choices (Verse, Bridge, Chorus) don't work here at all.
The song start with a brief 16/16 drumroll fading in, except this the song starts "in medias res".
There are four pre-choruses in the song, one of which is instrumental. The 4th measure features a 3+3+2 rhythmized scalar bass movement, m.7-8 features the familiar "Queen-cliche".

| F   | G   | C   |/B /A /G  |
| IV  | V   | I   | -        |

| F   | G   | C G/B | Am    |
| IV  | V   | I  V  | vi    |


| Bb  | -   |
| bVII| -   |

              C... | -    | -    | -   |
| Gm7 | -   | C    | -    | Bb   | -   |
|  v  | -   | I    | -    | bVII | -   | 

The first pre-chorus is accompanied with just piano and bass and some cymbals. From m13 the bass starts playing an ostinato (see also in "Kind Of Magic") that also works as pedal bass.
The second pre-chorus (starting the fourth cycle) adds somple backing vocal harmonies and drums. The last four measures are omitted.
The third pre-chorus is the backing of the first half of the guitar solo.
The fourth pre-chorus is shortened and extended as well. It starts harmony-wise from m7, melody-wise from 9th measure and its closing four measures are repeated.

Chorus
We have six choruses in the song two of which are instrumental. The choruses show an AA' inner form.
The (pedal) bass ostinato is kept played during the chorus. The "A" subsection too show an AA' inner form.
The chords root-wise strictly follow the lead melody (or vica versa) except the last note. The piano chords are played with sustain pedal. The first three notes show a 3+3 syncopation.

| C-ost. | -      | -       |
| C Dm F | (F)    |(F) C Dm |
| I ii IV| -      | -  I ii |

| C-ost        | -    | -    |
| F Em F Em C  | Bb   | -    |
| IV...        | bVII | -    |

2nd time ending

m5:
| Bb5  G5 | C5 G5 | D5 G5 | F1... G | (G)   |
| bVII V  | I  V  | ii V  | 4th   V | -     |

The first instrumental chorus has soft drumline. Measures 5-6 add chopped guitar chord.
The second chorus (vocal) in m 5-10 adds guitar trill on m7th-6th degrees.
In the third chorus the trill is moving up and down (reminiscent of the "Liar" outro). The 8th measure of the second subsetion is skipped and the last measure has a tremolo-bar guitar glissando down from G in octaves.
The fourth chorus does not have different ending for the second subsection except a downward galopping guitar figure introducing the guitar solo.
The fifth chorus is reserved for the tail-part of the guitar solo with sustained guitar harmonies. In the second subsection guitar harmonies dublicate the piano chords with a microscopic change (C chord instead of Em). The ending is different:

| C-ost.      | F E F E  C  | -          : bass
| F  C F  C - | F C F C  -  | -         |
| IV I IV I   | -           | -         |

The next measures belong to the pre-chorus.

The last chorus drops in the chopped guitar chord again then the Liar-esque moving guitar trills. Next to the complete chorus there is a long (8 cycle) sequence of repeatition the last vocal phrase fading out. Lead guitar fill with tremolo-picking added from the fourth cycle.

Verse
We have only two verses in the song both in the first half of the song. This section is the most responsible for the rock-n-roll feel. The phrasing 6+6+4+4+2+2, ABCC'DD'. "A" and "B" phrases are rhythmically similar. The chord progression of the first two phrases follow the double-plagal cadence.

| C    | -    | -    | -    | Bb   | -    |
| I    | -    | -    | -    | bVII | -    |

| F    | -    | -    | -    | C    | -    |
| IV   | -    | -    | -    | I    | -    |

| Gm7  | /D Bb | C    | -    |
| v    |   bVII| I    | -    |

| Gm7  | /D Bb | C    | -    |
| v    |   bVII| I    | -    |

/----- 2x -----\\
| F    | G     |
| IV   | V     |

The last two phrases add synth arpeggios.
The second Verse adds guitar fills in m6, m8.

Solo
The solo starts as an instrumental pre-chorus the guitar following the original lead tune for the first two phrases.
Next two 2 measure phrases play a guitar arpeggios both starting with 3+3+3+3 groupings. The second of these is closed by diatonic ascending guitar run in fast triplets arriving on the downbeat of the next subsection which is an instrumental chorus.