Since no one has chimed in, take a look at the LM3914. It can light LEDs at different frequencies. Also you can daisy chain them to get a higher range of frequencies.No!
The LM3914 is a bar/dot meter. It "measures" volume
, not frequency. You could build 3 (or more) frequency-filters and use one LM3914 for each frequency band. (That would work without a microcontroller.)
1 - Have like 3 colors of lights and each one is activated by a range of sound frequency, lets say:
a --- Red for kicks/basslines;
b --- Yellow for claps/snares;
c --- Green for Hihats
(the colors and quantity are just examples)
So basically it would work kind of like an equalizer;
That's sort-of possible. Except, hats, snares, and hand claps have very similar spectrums You will not be able to isolate them (if they are mixed).
There is a handy chip called the MESGEQ7]
that gives gives you the levels in 7 different bands.
2 - Have one color for each instrument in a band...
... i guess I had to bypass each mic before it goes into the mixer so each one is activated individually and still can mix the sounds on the mixer);
Right. You'd have to split the mixer inputs and run them into the lighting system as well as the mixer. And you'd probably
need a preamp for each signal, although with a mic directly in front of a kick drum or guitar amp may have enough signal to work without a preamp. Or, if your mixer has "sends" for each input, you can use the mixer's preamps. The Arduino Uno has 6 analog inputs. The Mega has 16 analog inputs.
3 - Having a set of lights respond to one single instrument and each color would correspond to a range of notes...
(from my knowledge of music, each color would represent a range of sound frequency);
Yes. With hardware filters (made with op-amps) or the MSGEQ7, you can split the audio signal into frequency bands and run each band into an analog input.
4 - Have a light blinking in sync with a " dubstep wobble bass" (i have this doubt just because it isn't the volume, its a frequency/LFO effect).
Again, if the music is mixed you can isolate the bass frequencies, but not the instruments. The bass signal will contain the kick drum and any other bass "notes".
I hope I didn't made it hard to understand.
Therefore, like i said previously, I want to know if each topic is possible and the necessary gear and also if i can combine some (like 2 with 3 and 1 with 4).
Sure, you can have multiple effects. Just count your inputs & outputs to make sure you have enough (You can use serial shift-registers or matrixing to expand the number of outputs). Just start-out simple and get something
working before you try to get too fancy.
Lights can be El Wire or LEDs, I suppose i can use one or another jsut by making slight adjustments to the circuit/layout.
You'll need to check the voltage & current requrements. You may need a MOSFET or something to boost the power. (Same thing if you connect multiple LEDs to one output.)