Emerson then switches to fast Eb-Minor and F-Minor ascending and descending hand-over-hand piano runs in the first 8 bars of the first "A" section when Lake first enters singing "Just take a pebble and cast it to the sea".
Emerson switches back to strumming the grand piano strings with a plectrum between the first and second "A" sections, while the bass and drums play.
The ostinato in the left hand may have been based on a similar one from Musica ricercata, movement VII by György Ligeti.
In the earliest live versions of the piece, as seen in the Pictures at an Exhibition concert film from the Lyceum in December 1970, Lake would sing a few verses of the folk standard "Old Blue" toward the end of his acoustic guitar interlude.
In later live versions of "Take a Pebble", the Greg Lake song "Lucky Man" (and later, "Still...You Turn Me On" followed by "Lucky Man" - as recorded on Welcome Back My Friends to the Show That Never Ends... Ladies and Gentlemen) was added to the Greg Lake folk-style acoustic guitar section, followed by a solo Keith Emerson jazz and blues piano medley of tunes (that the band would join in on the very end of), followed by a "Take a Pebble" band improvisation moving between F-minor and Eb-Minor (often featuring Palmer on timpani), and then the conclusion of the piece.