There is imitation between the voice and the electric guitar at points in the song, e.g. following the 'willing as' the guitar repeats the same notes in imitation bar 62 on beat 4.
The time signature is 12/8, which means that there are four groups of three quavers in a bar; this is a type of compound time signature. Many of the rhythms are dotted crotchet to quaver, which gives the song a swung feel. The tempo is at a steady 112 bpm. Syncopation is found at various points in the melody, which helps create the upbeat feel. Each new section begins with an anacrusis.
The tonic key of Killer Queen is E♭ major - however, the verses start in the relative minor of C and the choruses move to the dominant B♭ major. Both of these keys are the closest relations to E♭ major.
Not all of the chords used belong to the tonic key. For example, bar 18 has the chords G7, F7/A, G7/B and C. If all the accidentals in the key signature were used, these chords would actually be Gm7, Fm7/A♭, Gm7/B♭ and Cm. However, they have been altered to chords that don’t belong to the tonic key.
Extended chords, such as seventh and eleventh chords are employed. A harmonic pedal is used in bars 5 to 6 at the start of each verse to underpin the music. Mercury’s overdubbed vocal parts move in parallel harmonies, which makes the band sound bigger and helps differentiate between sections of the song.
Shared between the band members, a descending chromatic bassline is heard in bars 7 to 9, which highlights the flamboyancy of the song. A circle of fifths features at bar 20 where the chords are A - Dm - G7 - C, which are all closely related, as shown in the diagram below.
Some techniques used by the guitar include, a pitch bend at bar 30, a slide at bar 34, a palm mute at bar 69, and light distortion throughout. Freddie Mercury uses a portamento between the two syllables of ‘queen’ in each chorus. In bar 17 a flanger effect is applied to the lyric 'like a laser beam' to produce a sound of a laser, which is a technique known as word painting.
Many of the techniques used in Killer Queen that enhance the sonority of the song were added in the recording studio. These effects include reverb on the lead vocals and stereo panning. These can be heard in bar 19 and during the overlapping guitar parts in bar 55.