Combine two Arduino projects into one PCB with the Arduino codes combined.

Other Hardware Audio
7

Take the first code and replace the loop function of it with the loop function of the second.
Then add the

char customKey = customKeypad.getKey();

And change each

 if (digitalRead(A1) == HIGH) {
    tone(8, 494, 100); // play tone 59 (B4 = 494 Hz)

with a string of

 if (customKey == '*') {
    tone(8, 494, 100); // play tone 59 (B4 = 494 Hz)

Where '*' is the character you want to associate with that note.