Experimenting with the use of left pedal depress/release when the una corda string(s) is tuned to a slightly different pitch than the other string(s) in the same course, gives the possibility of changing timbre/pitch both suddenly and gradually.

In general, the same little motif of 3 tones/keys have been tested in different dynamics (forte and piano) and in 3 different ranges; middle range, very low range and the very high range.

The efficiency of the una corda pedal often varies from piano to piano. Ultimately, when the una corda pedal is depressed, one should hear only the pitch from the una corda-string, but often one can hear a little resonance from the other strings in the course. The timbral differences between una corda and tre corda are nevertheless clearly audible.