Compare and contrast the use of harmony and tonality of each of the prescribed works (Bach's Brandenburg Concerto no. 2, Kodály's Dances of Galánta), highlighting any significant musical links.

Bach’s Brandenburg Concerto no. 2 and Kodály’s Dances of Galánta come from two periods that have very different tendencies towards harmony. The Brandenburg tends to stick to using mostly chords of the ambient key, and the modulations tend not to be further away than one, or maximum two degrees of separation. Harmony techniques used include circle of 5^ths progression, pedal notes as well as more. In the Galánta, the harmony is more Romantic, including extended chords and spontaneous modulation, but also elements of folk music harmony. However, many similarities can be found between the two works. That being said, the detail of how they are implemented is almost always at least slightly different:

Both use diatonic functional harmony mostly using traditional major and minor scales (Bach primarily in F major, Kodály primarily in Am). However, Bach stays within at most 2 degrees of separation of the tonic, and Kodály explores keys more exotic to the tonic. Examples: Kodály begins in Am, but modulates into A♭m at 93 (which shares no notes in the scale with Am), and B♭ at 334 (which only shares 3 notes in the scale). Bach begins mvt 1 in F and modulates to C at 15 (dominant-tonic relationship). Even between movements he stays within close keys: F in mvts 1, 3, Dm in mvt 2 (tonic-relative minor relationship)Both make use of perfect and interrupted cadences to confirm key (perfect) or provide surprise and keep the music going (interrupted).
Perfect cadence examples: Kodály 49-50 B major – E minor to confirm new key of the new rondo theme in Em. Bach movement 1 8^2½-8³ C major – F major to confirm tonic key before the entrance of a solo episode.
Interrupted cadence examples: Kodály 211-212 V-VI in D major (A major – B♭ major) to provide a surprise effect but also modulate into E♭ for the next phrase. Bach movement 2 62-63 V⁷-vi^ø7 (A⁷-B♭^ø7) to prolong ending. However, Kodály uses interrupted cadences more often.Another type of interrupted cadence that both of them use is the tierce de Picardie, whether it be at the end of a movement or just a phrase. Effect of brightening
Examples: Kodály 112 A♭ major end of phrase in A♭m, Bach end of 2^nd movement D major chord instead of D minorBoth make use of circle of 5^ths progressions to travel through keys and chords. Examples: Kodály 483-484: (chord changes every half-bar) A minor, D⁹ (then D⁷ later in the beat), G^aug, C^maj7,#9 (then C^maj7 later in the beat), Bach mvt 1 40-47: (chord changes every second bar) D minor (D major in 41^4½), G, C, F. It should be noted that although the circle of fifths progression is a common trait of the Baroque period, it is not exclusive to the baroque period in the same way as the harpsichord is – Kodály’s use of it was not a pastiche of Baroque composersBeing a Romantic-20^th century piece, Galánta makes much use of extended chords (4+ note chords other than dominant 7^ths). However, Bach uses them occasionally as well. It should be made clear, however, that his use of them is very significantly less frequent than Kodály’s.
Examples: Kodály 66-67 chord of D⁹, then 68-69 G^11,omit3, (70-71 F64, not an extended chord. It is, however, a chord not in root position, which is more common of later periods than earlier, although by no means uncommon in the Baroque period either), 72 B^ø7. This phrase was in fact a development of a previous melody that used more basic diatonic chords (at 50, this time in Em not Am: [changing chord each bar] Em, Em⁷d, C, C^aug/B. As seen there are some extended chords but they are not as frequent as they are in the development). Bach 51 D⁹ chord (although it could be argued the E♭ in the flute and oboe is only a passing note or auxiliary), 112 B^o7 chord. Again, however, Bach uses these much more rarely than Kodály. In addition, Bach usually uses them for the purpose of modulating, while Kodály uses them as a method of developmentBoth make use of pedal/drone/held notes that do not always necessarily “go with” the chord above. Example: Bach, movement three 136-140 tonic pedal (F). The chords ([changing every half-bar] F, F⁷, B♭, F, F, F⁷, B♭, F) do in this case, however, fit with the F. This is not always the case in the Bach, but it is more common than in the Kodály. Kodály: 173-207 repeating (not held) pedal of open fifth D-A. Chords do not always fit with both notes (ex.: 197, G major chord suggested in melody [Picc.], countermelody [Cl. I] and some other parts such as glockenspiel). This is influenced by folk music (of Galánta), as drones are very common in folk music, especially of Eastern European origin.