Musical expectation

[oggy22]

Write an intelligent method that extends the tone sequence predicting its further development, or in other words, this method calculates the musical expectations.

For example given:
0,2,1,3 -> 2,4,3,5, etc. (C-E, D-F -> E-G, F-A, etc).
0,4,2,5 -> 4, 7, 5, 9 etc. (as above, but chromatically)
C,G,E,G,C,G, -> E,G, etc (Alberti bass)
E,D,E,C,E,B -> E,A,E,G#

Pseudo implementation (doesn't account for the last example where const tone is required)
Expectation(List seq)

for (int size = 1; size <= n-2; size++)
{
step = seq[size] - seq[0];
if (step applies for entire seq) return the extension;
}

[oggy22]

Duplicate of #88

[oggy22]

Duplicate of #88