He has developed a style of playing piano he terms "soft pedal". Debussy notes that the entire piece should be played with the soft pedal. I had a few spots where I wanted to soft pedal but maintain speed. The unit featured two brass pedals, right for sustain, left soft pedal or vibrato. The "una corda" pedal is also called the "soft pedal". The soft pedal or "una corda" pedal is placed leftmost in the row of pedals. The "soft pedal", or "una corda" pedal, was invented by Bartolomeo Cristofori.