Thank you for your patience PaulS 
I have problem with the syntax or i just implement it the wrong way (or probably both).
This is what i got now (but the problem is that it sends a note and immediately after a note off)
#include "Wire.h"
#include "BlinkM_funcs.h"
#include <MIDI.h>
byte blinkm_all = 0x00;
byte incomingByte;
boolean pushbutton_pressed = false;
boolean midiOffSent = false;
const int number_of_pushpins = 16;
int pushbutton_state[number_of_pushpins];
byte leds[] = {9, 10, 11, 12, 13, 14, 15, 16 ,17, 18, 19, 20, 21, 22, 23, 24}; // array for the i2c addresses of my blinkm's
int pushbutton_pins[] = {2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 16, 17, 18, 19, 22};
void setup() {
MIDI.begin(1);
Serial.begin(57600); // temporary so i can use spikenzielabs.com serial to midi app
BlinkM_begin();
for(int i=0; i< number_of_pushpins; i++){
pinMode(pushbutton_pins[i], INPUT);
}
}
void loop() {
for(int i=0; i< number_of_pushpins; i++){
pushbutton_state[i] = digitalRead(pushbutton_pins[i]);
}
for(int i=0; i< number_of_pushpins; i++){
if( pushbutton_state[i] == HIGH) {
if(pushbutton_pressed == false){
BlinkM_setRGB(leds[i],0x00,0x00,0xff);
MIDI.sendNoteOn(70,127,1);
midiOffSent = false;
pushbutton_pressed = true;
}
}else if (!midiOffSent) {
MIDI.sendNoteOff(70,127,1);
midiOffSent = true;
}
else{
BlinkM_setRGB(leds[i],0x00,0x00,0x00);
pushbutton_pressed = false;
}
}
}