Wow! What a fun jam last night!
The song of the week is 'Cry Cry Darlin'' in the key of G.
I learned this song from the following Bill Monroe recording:
Bill Monroe: key of A
But, here are some other good versions of the song to also take a listen to.
Alison Krauss: key of C (starts at 0:55)
Ricky Skaggs: key of G
Dolly Parton: key of C
Notice how the last two versions, while falling within the parameters of the Bluegrass genre (at least as it is now commonly understood), lean the song in a decidedly Country direction. If one considers how many artists associated with other genres of music come from Bluegrass backgrounds, how many Bluegrass artists have been heavily influenced by other genres, and how many elements of other genres were put together to create Bluegrass in the first place, it should come as no surprise that the dividing line between Bluegrass and certain other genres is at some points quite thin, and that in many of these cases, it will not always be clear where the Bluegrass genre ends and another genre begins or vice versa.
The chord progression for the verse (or A-Part, if you prefer to think of it that way) of Cry Cry Darlin' is the most common of all chord progression in Bluegrass:
The progression for the chorus (or B-Part) is:
Notice that the last two lines of the 'chorus' progression is the same as the last two lines of the 'verse' progression.
Other songs that have 55112255 for the first two lines of their chorus progression which are then completed by the second half of their verse progression include 'Old Home Place', 'I'd Rather Die Young', 'Next Sunday Darling Is My Birthday', and some versions of 'My Little Home In Tennessee'. Other instances in which 55112255 shows up in songs include the first half of the third verse of 'Sunny Tennessee', and the first half of what one might consider to be the 'pre-chorus' of 'Tall Pines'.
In the two other recent intermediate jam songs of the week that have been played at the jam with a 2 chord in their progressions ('I Can't Feel At Home In This World Anymore', and 'Homestead On The Farm'), the 2 chord is not necessary to use in the progression for the song: one can find recorded versions of these songs that do not use the 2 chord that sound musically correct (though perhaps not always quite as interesting), and the same is true of many songs that are commonly played in Bluegrass circles with a 2 chord. The main reason for this is that, for a song that uses no notes in its melody other than that of the Major Scale, no Major chords other than the 1, 4, and 5 are needed to harmonize the melody, for together, these three chords contain all 7 notes that make up the Major Scale, and they are the only Major Chords that contain no notes that are not part of the Major Scale.
In the case of 'Cry Cry Darlin'', however, the main melody note in the 6th measure of the chorus/B-Part (a C# note when the song is played in the key of G) forms a severely dissonant interval with the root notes of the 1, 4, and 5 chords, and also with one of the other notes in the 1 chord, and in the 4 chord. The note in question happens to be the one and only note in the 2 chord that is not part of the Major Scale. When played in the key of G, the first half of the chorus/B-Part of Cry Cry Darlin' uses in its melody all, and only, the same notes that make up the D Major Scale. The three chords that are used for that part of the song when played in the key of G also happen to be the same chords that are the 1,4, and 5 chords for the key of D, namely D, G, and A. (Conversely, the 1,4, and 5 chords for the key of G are the 4, b7, and 1 chords respectively for the key of D. G and D are closely related keys: the G Major and D Major Scales share 6 of their 7 notes in common with each other.) For these reasons, it is possible that some people might find it helpful to think of that part of the song as involving a modulation to the key of D when we play it at next week's jam.