Electronic Vocal Polishing

Baji J. Ram Rao
08:08 +0530 Fri. 22-Nov-2013

A friend of mine asked me, if it was possible to take an audio recording of a Bollywood song, and strip out the vocals to create a backing track.

The owner’s manual of the Yamaha PSR-E343, a budget priced portable keyboard says,

“When the sound of the external audio device is output through this instrument, you can cancel or lower the volume of the sound located in the center of stereo playback. Since most melody parts such as vocal are located in the center of the stereo sound, you can use the function to cancel the melody part then practice it via the keyboard.”

I doubt if it will work -- will someone please confirm?

Getting a computer to recognize audio chords from a piano is extremely difficult.
There are definitely some expensive software products that try very hard to do this.
It’s called vocal polishing -- removing or correcting wrong notes in piano recordings; changing the chords in a guitar accompaniment after the recording is over.

Enter Melodyne editor -- flagship software product from Celemony Software GmbH of Munich, Germany. The stuff of dreams.

It is an audio software app. for Apple OS X or Windows with which the user works with notes, rather than meaningless wave forms.
Besides seeing where the music gets louder or quieter, one also sees where notes begin and end and at what pitch they lie.
One can modify each note and thereby influence directly the intonation, phrasing and dynamics.
This can be done not only with vocals and monophonic instruments but with polyphonic instruments such as pianos and guitars as well.

Working with Melodyne is like being able to say to a vocalist “sing this note a bit longer” or to a pianist “give slightly less weight to the third in this chord” – hours, weeks, even years after the recording session.
While it might just about work with a clean audio recording of a single instrument like a piano or a guitar, it’s close to impossible to do it in a full orchestral recording.

At the present time, this is still an area where the human mind has an advantage!
A little like trying to recover eggs, flour and sugar out of a cake, huh?