Just a summary plus some organisation

Tonal features of Mars

Tonic-dominant relationship, emphasised by persistent ostinato pedal

Strong tonal centre around C

Treatment of motifs - intervallic expansion (Ex. 6-1, Ex. 7) - KIV, this heading may not be suitable for this point

Lots of triadic harmonies used (Ex. 3, Ex. 7)

Resolved dissonances (Ex. 8)

Non-tonal (?) features of Mars

Use of mixed modes (Lydian and Aeolian) - KIV, may not be significant

Instances of unresolved dissonances (Ex. 5)

Triads moving in parallel motion. Progressions don't follow functional harmony (Ex. 3)

Phrase structure cannot be discerned based on cadences alone, especially when melodic lines just move in one long strand (Ex. 3-2 and Ex. 3-3). Instead other musical features come into play. Dynamics play a crucial role in determining the phrase structure here. A sense of the phrasing can be felt with the swelling cresc. and dim. dynamics within the bar. Also, the 1-bar phrases are marked by the repetition of the head tune.

The melodic motif impacts the harmonic progression. Take the motif Db-Ab-G. It seems that there's an Ab maj triad (with 3rd missing) going to a G maj triad (Ex. 9). I can't determine whether it's really meant to be a major triad but I guess by looking at subsequent bars, one can infer that the major sonority is something Holst wants to use. The Ab maj triad to G maj triad somehow reminds me of some neapolitan relationship (in G major). However, if I remember correctly, neapolitan chords are pre-dominant in nature, so in this way, rules of functional harmony aren't applied here. Contrast this with the horn part of Ex. 7. The altered motif is clearly in the key of Ab major, and diatonic harmonies are used.

Ex. 9