The sound is amplified by means of the soundboard which is a large flat piece of wood which effectively acts as a large loudspeaker. To see a diagram of an upright piano action click here . Concert pitch means merely that the note A above middle C is vibrating at exactly 440 times per second. A above middle C would be vibrating at less than 440 times per second. Go to The Auditorium to hear C at concert pitch.
Grand pianos come in many different makes, types and sizes.
Grand pianos are considered to be better than upright pianos for two reasons. Concert grand pianos are over nine feet long. The sound they produce is very powerful. You can hear the difference in bass tone between a baby grand and a good upright in The Auditorium To find out more about the workings of a grand, visit the page about grand piano regulation. These terms are not really in use any more.