The song of the week is 'Wreck Of The Old '97' in the key of D.
The chord progression is:
(Prog. V7 on the Basic Chord Progressions chart; this is the same progression that is used for Bury Me Beneath The Willow and A Memory Of You.)
In the key of D: 1=D, 4=G, 5=A.
The D chord consists of the notes: D, F#, and A
The G chord consists of the notes: G, B, and D
The A chord consists of the notes: A, C#, and E.
Together, these notes make up the D major scale: D, E, F#, G, A, B, C#, and the melody of Wreck Of The Old '97 uses all the notes of the scale.
Wreck Of The Old '97 has no chorus. There are 6 verses for the song, but it is common for only 5 verses to be used for the song.
While Wreck Of The Old '97 uses a very common chord progression - the most common of all progressions in bluegrass, there are some things about its melody that are uncommon in bluegrass. For instance, in the second line, at the point where the change to the '5' chord occurs ('A' in the key of D), the melody hangs on the 7th note of the scale ('C#' in the key of D), whereas it is far more common in songs for the melody to go the 2nd note of the scale ('E' in the key of D) at this point instead when the second line of the progression for a song is 1155.
Here are some good bluegrass versions of 'Wreck Of The Old '97' to listen to:
Flatt And Scruggs: key of Bb
The Osborne Brothers: mandolin intro break and verses in the key of E; fiddle break in the key of A; banjo break in the key of B
Mac Wiseman: key of D
In the attachments, I have included 2 guitar tabs of the melody: one written in the key of D, and one written in the key of C. The locations of the melody notes on the fretboard in the 'C' tab make the 'C' tab more conducive than the 'D' tab to working out a Carter-style break for the song. If for this reason, or some other reason, you choose to work with the C tab instead of the D tab, you will need to capo the 2nd fret in order to be playing the song in D. I have also included 2 banjo tabs of the melody, one in D and one in C. Since the lowest note of the melody is the 1st note of the scale (a 'C' note in the key of C, a 'D' note in the key of D), you will need to tune the 4th string of the banjo down to a 'C' note if you choose to work with the key of C banjo tab of the melody given here. Capoing to the 2nd fret will then raise the pitch of the 4th string back up to a D note.
Additional Points of Interest
If you are interested in learning about the history of the song, here is a good article on Wikipedia to check out that deals with both the historical event that the song is about, and with the history of the song itself:
For those who are interested, here are a couple of non-bluegrass versions of 'Wreck Of The Old '97' that I was familiar with before I got into bluegrass music. The second one is the second-oldest recording of the song, dating from 1924, and was the first million-seller 'Country' record. It has been many years since I have seen a copy of the old '78 record, but I recall that the B-side of the record was 'The Prisoner's Song', another old 'pre-bluegrass' classic that has been adopted into the standard bluegrass repertoire.
Johnny Cash: key of Bb
Vernon Dalhart: key of D