An Irish "session" is a gathering of musicians (often taking place in a public venue) for the purpose of playing music together. Playing in a good session can be a fun playing experience, and a great chance to improve your music--all at the same time. Good sessions can produce some of the best Irish music in the world, and they can do so for hours on end--under the right circumstances.

There is a popular misconception that "The Irish session" is meant to be an open forum, where anybody who can come in off the street is welcome to participate and learn to make music at the same time. In reality this characteristic is not intrinsic to "the session" itself, and it can be a big mistake to incorrectly assume that it is.

In reality, Irish sessions are much more like other casual social gatherings than they are like open forums. Often, sessions are groups of friends getting together for a few tunes, and not as an open invitation to everyone to come and play. People who come in off the street will usually be welcomed, but they may be met with a certain amount of circumspection until they demonstrate their ability to "play well with others."

Here are some of the bigger mistakes that will alienate your fellow musicians at a typical session:

• Playing a percussive instrument poorly, out of turn, too loudly, or generally outside the taste of the other musicians. A good rule of thumb here is:   "One bodhrán and/or guitar/bouzouki at a time."  More than one will often clash, irritating the melody players. In Irish music, the melody is FAR more important than the backing, and backers who assume otherwise can quickly become session-pariahs. Bones and spoons should be used sparingly if at all and only after asking to use them. (Tuesday nights at O'Flaherty's are a "bone free zone!" Bodhran participation is managed by the session leader and the resident Drum Section!)
• Joining a group of unfamiliar musicians without asking, or without being invited. This is especially important if you think your presence might change the existing dynamic in a way that the musicians don't want it changed. The quality of the music is often what determines how much fun people have. If you ruin their music, you are probably ruining their fun too.
• Playing when you don't really know the tune. It's usually ok to do so very quietly, but... be careful! Your wrong notes may distract and irritate the person sitting next to you. (Please leave sheet music at home.)
  
• Starting too many tunes without consulting the other musicians. It's generally a good idea (especially at an unfamiliar session) to ask the other musicians if they'd like to play a tune before you launch into it. This helps you make sure that you won't be doing something antisocial by starting a tune that the other musicians don't know or don't want to play.
• Failing to tune your instrument before sitting down to play (and periodically during the session, but not so you bother players sitting next to you).
  
• Ignoring established tempo. It's not the speed of your playing but the quality of the music that impresses and keeps a session cohesive. It's never a race to the finish line!

When someone does any of these things at a session, it makes everybody feel uncomfortable. While it might be nice (especially for beginners) if the other musicians would politely inform you about the "rules," this is difficult to do tactfully, so this isn't usually what happens. Instead, the other musicians are more likely to simply feel irritated and leave it at that.

In general, remember this: If you're not organizing the session, you are a GUEST, and all the same social guidelines apply to your "visit" that would if you walked into someone else's party. Just as you can alienate people by crashing a party and being rude, so too can you alienate them by crashing their session and being rude. No one likes to feel like they're being held hostage by insensitive players.

 Session players who read the information at the link below were astounded I'd waste my time explaining something so obvious. I pointed out to them that not all folks reading it would be familiar with these "rules." Some persevered that even the completely unindoctrinated would, by means of common courtesy, never need to be "told" about any such "rules." I didn't think of it at the time but I should have responded: