Modifying Auduino Code: Wrestling with RAM

Projects Programming
3

From your code:

// Key of C ........C D E F G A B
uint16_t majorC [29] = {  
    274, 308, 346, 366, 411, 461, 518,
    549, 616, 691, 732, 822, 923, 1036,
    1097, 1232, 1383, 1465, 1644, 1845, 2071,
    2195, 2463, 2765, 2930, 3288, 3691, 4143, 4389
       };
 
uint16_t mapMajorC(uint16_t input) {
  PROGMEM prog_uint8_t value = (1023-input) / (1024/29);
  return (majorC[value]);
}

You have the PROGMEM in completely the wrong place. What you need is something like this:

// Key of C ........C D E F G A B
PROGMEM prog_uint16_t majorC [29] = {  
    274, 308, 346, 366, 411, 461, 518,
    549, 616, 691, 732, 822, 923, 1036,
    1097, 1232, 1383, 1465, 1644, 1845, 2071,
    2195, 2463, 2765, 2930, 3288, 3691, 4143, 4389
       };
 
uint16_t mapMajorC(uint16_t input) {
  uint16_t value = (1023-input) / (1024/29);
  return pgm_read_word_near(&majorC[value]);
}

However, if you are using the equal tempered scale, why not have just one table giving the frequency for each note, then play scales by moving up/down the required number of semitones from the starting note?