Most fiddle tunes have two parts, called the A part and the B part. Each part is eight bars long, and each part is played twice. Players write this form as AABB. One time through the tune is 32 bars. Once you know the form, you can keep your place in a tune you have never heard.
The A part and the B part
The A part is the first melody. It comes first and gets played two times in a row.
The B part is the second melody. It follows the A part and gets played two times in a row.
In many tunes one part sits lower on the instrument and the other sits higher. Old-time players call these the coarse part and the fine part. The coarse part is the low one. The fine part is the high one.
Soldier’s Joy, Liberty, and Arkansas Traveler all follow the AABB form.
How to count it
Count bars, not notes. Tap your foot twice in each bar.
A part, first time: bars 1 to 8.
A part, second time: bars 1 to 8 again.
B part, first time: bars 1 to 8.
B part, second time: bars 1 to 8 again.
Most eight-bar parts break into two halves. The first four bars ask a question. The last four bars answer it. The end of the part lands on the 1 chord, the home chord of the key.
First and second endings
The last bar or two of a part can change on the repeat. The first time, the ending leads back to the start of the part. The second time, the ending leads on to the next part. Sheet music marks these as a first ending and a second ending.
When you learn by ear, listen for this. The first seven bars are the same both times. Only the last bar or two differ.
The chords follow the form
The chord pattern is eight bars long too, and it repeats with each part. Learn the chords for the A part and the chords for the B part, and you can play backup for the whole tune.
In some tunes both parts use the same chords. Boil Them Cabbage Down is one. In others the B part brings in a new chord. The B part of Old Joe Clark uses a G chord in the key of A. Players call it the flat 7. Read the Nashville number system for bluegrass jams.
Angeline the Baker uses only two chords, D and G, through both parts.
How the form works in a jam
In a bluegrass jam, one time through AABB is one break. The leader plays the tune once. Then each player in the circle takes a turn, one full AABB each. Players who are not taking the break play backup.
This is where counting matters. When the fiddle player takes a break, the banjo player needs to know when the second B part ends, so the next break starts on time.
Listen for the turn from the second B part back to the A part. The melody drops back to where it started, and the next player comes in.
The leader ends the tune by calling “last time” or lifting a foot during the last pass. Read how to end a song in a bluegrass jam.
Old-time jams use the form a different way
In an old-time jam, everyone plays the melody together, and nobody takes a break. The tune goes around many times, AABB each time, until the lead fiddler signals the end. Read bluegrass vs old-time music.
Tunes that break the pattern
Not every tune is 32 bars of AABB.
Some tunes have three parts. Players call them the A, B, and C parts.
Some tunes have a part that does not repeat.
Some tunes have an extra beat or a missing beat in one phrase. Players call these crooked tunes. They are more common in old-time music than in bluegrass.
When someone calls a tune like this, they often say so first: “This one has three parts,” or “The B part is crooked.”
The kick-off
A fiddler often starts a tune with a short rhythm on one or two notes before the melody begins. Players call these potatoes. The potatoes set the speed and tell everyone when to come in. Read how to kick off a song in a bluegrass jam and how to play the fiddle shuffle.
How to keep your place
Hum the melody in your head while you play backup. This is the best way to know where you are.
Learn what the end of each part sounds like. Most parts end with a clear landing on the 1 chord.
If you get lost, stop playing and listen for the start of a part. The return to the A part is the easiest spot to hear.
Use the form to learn faster
A 32-bar tune has only 16 bars of new music, because each part repeats. Often the two halves of a part share notes too. Learn the tune in four-bar pieces. Read how to learn a fiddle tune by ear.
For tunes to start with, see fiddle tunes to learn first for a bluegrass jam. For the instrument, read the bluegrass fiddle guide.