Erasing the Soloist
In past experiments I have only created orchestral accompaniment
for pieces where I
could get a recording of the orchestra "minus" the soloist. These
have all come from the folks and Music Minus One, though another
alternative would be just do the recording myself. Unfortunately,
MMO has only a small library of standard favorites which doesn't even
include the world's most poplular oboe concerto (Mozart). So while
MMO might have covered the "greatest hits" of the piano and violin
literature, overall their coverage is sparse.
In this experiment I have tried to remove the soloist from a "full" recording
via signal processing means. I began with a very nice recording
of the Strauss Oboe Concerto with Alex Klein and the Chicago Symphony
Orchestra. I then matched this audio to an electronic score of the
piece through polyphonic score matching. (You can read about this technique
in my papers if you are interested.) Then, I simply zeroed out the
regions of the spectrogram corresponding to the harmonics of the oboe.
I then resynthesize using phase-vocoding.
Of course, one should expect a certain amount of damage due to such a
procedure. In an unusual twist of fate, however, forces seem to
conspire *in our favor* in this application. To a significant
extent the live player, who plays at the same times and frequencies
of the recorded soloist, occludes the parts of the spectrogram where
the most damage has been done.