Yeah, I went ahead and tried it out again to make sure I really could do this. It seems that you reach a certain level of competency and the skill that is required to achieve all levels of once pitch can instantly be transferred to any of the other pitches.
This skill in my experience is as follows:
The ability to maintain an internal representation of the target pitch in short term memory by which to compare each egg.
The ability to 'set' the target pitch as a tonic so that one then hears the pitch as a tonal center which adds another cue by which to locate the pitch within chords and melodies.
Once these two are established, the last little bit that helps is every time the target pitch is heard, the internal representation of it is again reinforced and continues to be maintained throughout play.
The only thing I've found that throws me off is a strong dislodging of the target pitch as a tonal center.
I've begun to experiment at the piano with possible melodies and cadences that have a strong functional drive toward various tonalities. These would be applied in additional advanced levels.
My experience with APA has been that somewhere around level 312 of any pitch, the program glitches and doesn't go farther. I figure with these tonally driven melodies and cadences, we could push things into the 500's and possibly knock out one of the strongest remaining hindrances to unearthing and forcing chroma perception.
Space, you have a point here. APA doesn't really require you to store the chroma in long term memory as the pitch is recalled so often. I have only completed the demo so I'm not sure how the advanced levels are but it would help to, at some point, suppress the melody trigger and increase more and more the space between repetitions of the target tone.
Also, you're idea of having a different target tone at each chicken is good, but it should only come after the two or more tones have been properly memorized otherwise you would end up in the same situation as before where you have to play the target tone before each chicken. If they have been memorized, APA could just announce the target tone name instead of playing it.
I think the game levels could go like this for example:
1 Complete C level (should be memorized at the end)
2 Complete G level (should be memorized at the end)
3 Alternate chicken with C and G
4 complete D level (should be memorized at the end)
5 Alternate chicken with C, G and D