Dave on the banjo-l list, asks:
When a song is played that you don’t know, how do you:
- Remember the chord progression?
- If you don’t know the chord progression when you start, then how do you play backup to it?
Starting with #2:
Look at the guitar player’s left hand. If he/she is capoed in the same place as you, just match their chords. If there’s more than one guitar player, pick the one you think is most dependable, and you can see best. If you don’t have a view of a guitarist’s right hand, then move to where you do.
Folks on the list have already pointed out the value of learning chord progressions in terms of the simple number system, 1, 4, 5 and so on. This can be very helpful in learning chord changes. The value of using numbers is that, regardless of the key chosen, the *numbers* of the chords played to a certain song stay the same. Once you’re comfortable with the numbers as equivalents to say, G, C, and D, you can memorize progressions in terms of the numbers. Example: “Starts on a 1 (as usual), stays there for a pretty good while, ends up on a D. Then back to 1, into 4, and then the last line is 1 5 1.” That would be “Roll in My Sweet Baby’s Arms”. It reduces to: Long 1, 5, then 1 to 4, then 1 5 1. This is true in any key you play the song in, whether G or C, etc.
Many people when *reading* chords from a book or another player don’t also make a point of memorizing the changes. If they make the effort while they start playing and following the chords, after a few times through, they can start putting in the right chords “without peeking”. This means *not being content to just read* the chords, but actively memorizing them. Most bluegrass songs’ chord progressions are not very complicated, and the more someone practices memorizing chord changes, the faster and more accurate they become at doing so. (Surprise!!??)
It gets another step more valuable yet, when you start to recognize the *sound* of a 5 chord, or a 4 chord. G going to C (1 to 4) sounds different from G going to D (1 to 5), or G staying on G. Some melodies fit so nicely over a G to C chord change, and indeed, on investigation, you’d find that the melody notes fit the G chord at first, and at the time of the change to C, the melody arrives at least one note that is actually part of the C chord.
After a while, your ear starts to recognize these things. You start hearing where a melody is heading and something tells you that a 4 chord, or a 1 chord, etc. will be the one that sounds like a fit. Whether you’re right or wrong, trying to anticipate chord changes keeps the ear/brain combo in “active” mode, and that makes for better memorizing.
The above tells you some of the pathway, but it’s up to you to get on there and start traveling. It’s the doing that creates the success.