Be in tune. Before starting and whenever in doubt, use an electronic
Be on the right chord.
Remember the chord progression.
If necessary, watch the left hand of someone who knows the chords.
Stay with the beat.
It helps if you:
Recognize common guitar chords by sight even if you don't play guitar.
Help with the singing. Knowing the verses to songs is a key ingredient.
Suggest songs easy enough for everyone to follow. Be aware of common
denominators of ability when picking keys and tempos.
Know the basics of simple key transposing, such as when capos are used.
be on the right chord, tuning, etc.
Watch your volume.
Allow featured singer/soloist to be easily heard. If you can't hear
him/her, get quieter.
When it's your turn, make sure you're heard.
Be aware that your instrument (banjos especially) may not seem as loud
to you as to someone who's in front of it.
Know the traditional unspoken ground rules (see below).
Give everyone a chance to shine. Be encouraging.
Traditional unspoken ground rules:
Whoever is singing lead or kicks off an instrumental usually leads the
group through the song, signaling who takes instrumental solos
("breaks") and when to end.
Typical arrangement formats:
On a song when there are few or no instrumental soloists: The singer
starts tune any way comfortable, others join in, play until verses run
out. Or the singer can give a solo to anyone willing, following format:
On a song when some instruments can solo:
Break ("kickoff"), verse, chorus,
Break, verse, chorus,
Break, verse, chorus
[optional: add solo(s) and final chorus]
On instrumentals, the same person usually starts and ends, with solos
going around in a circle to those willing. Most common end: double
"shave and a haircut" lick.
Regarding solos ("breaks"):
Breaks for songs generally follow the melody and chords of a verse.
At the beginning of a song and following each chorus, the singer offers
breaks. Head signals and body language are used to offer,
If no one can solo, the singer just keeps singing verses and choruses to
If there are more soloists than there are verses of the song, some solos
can be grouped together to give everyone a turn. Or the singer can
repeat verses to lengthen the song.
If there are more than enough spots for breaks, some soloists can take
an extra turn.
If an instrumental soloist starts late, listen for whether the break is
starting from the top or from a later point in the song. If different
players realize they seem to be at different points in the song, try to
resolve it quickly, usually by falling in with the soloist, even if
he/she is mistaken.
When the lead singer doesn't start a verse on time, keep playing the
root chord and wait until the singer starts before going to the chord
Sing harmonies on choruses only, normally. Verses are sung solo. But in
less advanced jams, people may often sing along on the verses too, even
if not singing a harmony.
Use signals to help everyone end together: Foot out, hold up instrument,
end after "one last chorus" or repeat of last line. Listen for
instrumental licks that signal ending.
Some key participants may have main influence over the choice of songs
and who gets to do what. Be respectful of the situation. Fit in as
Instrumentalists, be mindful of when others want to solo or do featured
backup. Give them space and take turns being featured. Don't compete!
Re tuning: wait your turn. If someone is tuning, avoid any playing, or
perhaps (if you're sure your instrument is in tune) offer notes matching
the open strings of the other person's instrument.
In more advanced jams, often the "classic" arrangement of a particular
number is followed, including choice of key, which instrument solos
when, harm ony parts, etc. However, if the classic version is in a key
that doesn't work well for the lead singer, the singer calls the key and
the others adapt.
If you don't fit into one jam, look for another or start another, or
just stay and listen. (Note if there are already enough of your
instrument in the group, or if the speed or difficulty of the material
is out of your league.) In some situations it's OK to play quietly in an
"outer circle", not trying to be heard in the inner circle.
Pay attention and learn from experience.