The slow movement, an "Andante sostenuto", is the centerpiece of the Sonata. The "Nocturne in B major" is initially marked "andante sostenuto" and is in 4/4 meter. This piano has four pedals&colon; damper, sostenuto, una corda, and half-blow. The "Adagio sostenuto" theme appears in Eric Carmen's 1975 ballad "All by Myself". On grand pianos, the middle pedal is a sostenuto pedal. In 1874, Albert Steinway perfected and patented the sostenuto pedal. The sostenuto pedal was originally called the "tone-sustaining" pedal. Not all pianos have a sostenuto pedal, however. Other American piano builders quickly adopted the sostenuto pedal into their piano design. Chopin ends the sostenuto with extreme harmonic subtlety and delicacy. The A section is marked leggero, and the B section sostenuto. Optical sensors are also used for the damper, soft and sostenuto pedals. Usually, the sostenuto pedal is played with the right foot. Sostenuto for all manuals and the pedal. A final statement of the first theme leads into the coda, marked "Sostenuto ed espressivo".