Asklemmy

Composers write the music, musicians play the music, and conductors wave around a stick to keep the musicians playing the composition at the right volume and tempo, and to make sure the different sections of the orchestra (the different groups of instruments) come in and out at the right times.

Try coordinating all that without a conductor and it’d be a crazy cacophonous mess…

Fun fact, if you’ve ever watched a string quartet performance, the first violinist basically conducts the other three with their body and bow while playing. Most people have some natural tempo, but keeping multiple people on track usually requires visual queues and well-timed breathing.

In addition to all the good answers previously given, a conductor interprets what the composer has written. And different conductors may create very different interpretations of the same piece. They can set the basic tempo faster or slower, they can get the orchestra to really lean in to a particular musical phrase or de-emphasise it, they can bring out the horns at one point or hush them a bit and let us focus on the oboe or piccolo... A good conductor has studied and notated the entire score for some time before they and the orchestra even begin to rehearse.

So, part of that bow at the end can be to say, "what do you think of this interpretation compared to all the other times you've heard this famous symphony?" Then they usually turn around and wave the orchestra members to stand, which means, "and didn't these guys do a great job executing it!?"

Keeps the beat and tells you to ramp up, ramp down (volume ) and when to stop or start. He points the stick at your instrument group, makes eye contact, to let you know.

I was only in band (we had band not orchestra) in 5-8th grade.

But I'll tell you, it's very intuitive. I never was like "what's he mean?".

It's just like very obvious what the conductor* is indicating to you.

The secret is in the practice before the concert. Over many weeks, months the conducter truly “sets the tone”, listening to each individual instrument, their interplay, the tempo, the balance. The conductor knows the weaknesses and strengths of the orchestra, and during the concert uses the stick to create accents, to control the speed, to make sure any hurdle is removed. It doesn’t have to be either a stick, some use just their hands.

They wear VR contacts and are tapping little people on the "screen" to make the noises.

They’re kind of a live mixing engineer, it’s really hard to coordinate a piece between more than about 6 others without a conductor to give feedback, cues, and tend to the overall sound (tone, dynamics, rhythm).

1. It's like a semaphore type thing, the position of the baton shows where the beat is, and the conductor can signal other things as well like "emphasis here" or "quieter" with body language. An orchestra where everyone does their own thing wouldn't sound very good.
2. It's hard to get up and bow with certain instruments, there might not be space, and you couldn't see past the first row very well anyway. I always assumed the bow by the conductor was on behalf of everyone.

Keeping the music out of their eyes

It is the conductor.

I feel this video of Jacob Collier conducting an orchestra from scratch may be the best representation of what conductors do.

What composers are doing when they wave around that tiny stick is probably the same thing the rest of us are doing when we wave our tiny sticks around.

But for what conductors are doing, see the other answers here.

Essentially, musicians in an orchestra play the instruments, while the conductor plays the musicians. In both contexts they guide the instrument to make a specific note at a specific time, intensity and timbre, for a specific duration.

As for how the musicians interpret the movements, not sure. Perhaps it's unique to every orchestra and relies on the familiarity between musician and conductor.

https://youtu.be/lS64HqZbWHM

This gives a good overview I believe

Funny thing is you can actually conduct pretty well with just your hand.

Also a good conductor is usually an astoundingly good player of multiple instruments themselves.

It's kind of like how football (soccer) team managers are retired players that can still play better than the entire stadium wearing loafers and a suit.

Setting the tempo and keeping the instruments all synchronised

Players are playing instruments. Conductor is playing the players.

It is all about direction and control of sound.

This explains is pretty well:

https://www.bbc.com/culture/article/20141029-what-do-conductors-actually-do

I just recently attended to the Opera "The magic flute/Die Zauberflöte" so reading the replies here gave me a lot of answeres to questions I was to lazy to ask for myself.

Anyway, have soneone else here seen that play?

This is rage bait