The music of the Progressions Catalog encompasses a fairly wide range of styles, meters, tempos, and keys:
A majority of the Progressions suggest what could perhaps best be described as a folk/pop style of music. However, a number of other musical styles and influences (including jazz, blues, Classical, Latin, and rock) are touched upon throughout the Catalog.
Note: Specific meters as indicated in the Catalog listing are highlighted in bold
134 of the 168 Progressions (80%) are in 4, including 37 that are in 12 (4 with ternary division of the beat), 2 that are mostly in 4 with occasional measures of 6 (4,6), and 2 that are mostly in 4 with occasional measures of 3 (4,3). Another 23 Progressions are in 3, including 9 that are in 9 (3 with ternary division of the beat), and 4 that are mostly in 3 with occasional measures of 4 (3,4). Another 9 Progressions are in 6 (2 with ternary division of the beat), and the other 2 Progressions are in 2.
89 Progressions, or slightly more than half, employ a metronome setting (MM) between 110 and 130. The metronome settings for the remaining 79 Progressions are as follows: 13 fall between 131 and 139, 14 are 140 or above, 11 fall between 105 and 109, 12 fall between 95 and 104, 11 fall between 90 and 94, and 14 are 89 or below.
Of the 168 Progressions, 42 are in multiple keys, for the most part employing two keys, but including one that employs three keys, and another that employs four keys. Generally speaking, the most common way of modulating between keys is by raising the key one half-step, usually toward the end of a song. However, this type of modulation is used for only 5 of the 42 multi-key Progressions. For 8 of the multi-key Progressions, the initial key modulates to a key the tonic note of which is a whole step higher than the tonic note of the initial key (for example, G Major to A Major, or D Major to e minor). For 7 other multi-key Progressions, the modulation is between the Major and minor keys based on the same tonic note (for example, C Major and c minor). For 10 other multi-key Progressions, the interval between the tonic notes of the two keys is a 3rd (for example, C Major and A Major), and in 3 instances the relationship of the two keys is relative minor and relative Major (for example, G Major and e minor, or C Major and a minor). For 7 other multi-key Progressions, the interval between the tonic notes of the two keys is a 4th. The 5 other multi-key Progressions are the one that employs three keys (D Major, d minor, and G Major), the one that employs four keys (F Major, Gb Major, G Major, and Ab Major), and three for which the interval between the two tonic notes is a 5th.
The 45 additional keys given by the multi-key Progressions, together with the keys for the 168 Progressions, makes for a total of 213 keys. 177 of these keys, or more than 80%, are included among the 9 common keys of play on the guitar, and distributed as follows: A Major (26), a minor (13), C Major (27), D Major (27), d minor (12), E Major (19), e minor (18), F Major (17), and G Major (18). The three minor keys account for 43 of the 177, which is a somewhat greater percentage of minor keys than is normally the case in the corresponding genres of music. The six Major keys are all well represented, although there is somewhat less of an emphasis on the key of E Major, and especially on the key of G Major, as compared to what is normally the case for the corresponding genres of music. The other 36 keys (213 minus 177) most notably include B Major (9), b minor (7), c minor (6), c# minor (4), and g minor (4). Of the 36, 22 are minor keys, or more than 60%, which is clearly a much higher than usual percentage. All together, 65 of the 213 keys (about 30%) are minor keys, which again is somewhat higher than the percentage of minor keys typically found in the corresponding genres of music. This weighting toward minor keys is probably due to my lifelong observation and conviction that music in minor keys tends to be more expressive and more emotive than music in Major keys.