7 lessons I learned about chamber music over the years

Chamber music is an integral part of the artistic life of a musician. Playing a (more or less) complete instrument like the accordion makes it sometimes difficult to approach playing with others. Chamber music is an integral part of the musical education of a pianist or a violinist, for example, but luckily it has become a part of the accordionists' daily life too over the past few years.

Here are some of the things I have learned about chamber music over the years:

This goes without saying, learn your part before the rehearsal with your chamber music group. It will spare everyone a lot of time and make the time spent together more productive. I have seen a post on Facebook some time ago which pretty much summarizes this point: Rehearsals are the place to learn everyone else's part, not your own.
Breathe together. When you breathe with your chamber music partner(s) you will always play together. You won't even need to look at them for a queue.
When you play your part, listen to the other parts as if you were playing them. Keep an ear open and listen to what the others are doing. The other ear can listen to what you are doing ;)
Know when to change roles. If you are more inclined to being a soloist, it is good to learn when it is your time to go into the background and leave space to the other instrument(s), accompanying them.
Show up early for the rehearsals. It is always a good practice to show up at least 30-45 minutes early to a rehearsal. This is a true story, I was rehearsing with an ensemble at the Musikverein in Vienna and was punctual to the first rehearsal to the second. After noticing an unsatisfied look on the manager's face, I had a brief chat with my professor at the time. He advised me to be sitting on the stage, READY, at least 30 minutes before the rehearsal. The manager's attitude changed immediately.
Focus on building a common sound. You are not individuals playing together at the same time, you are parts of a bigger instrument which works together. Balance your sound accordingly.
Communicate with one another. Talk about what works and what doesn't work. If you have an idea on how to improve a part, speak out and try it out. Be open-minded and respectful.