<P> While clavichords were typically single manual instruments, they could be stacked, one clavichord on top of another, to provide multiple keyboards . With the addition of a pedal clavichord, which included a pedal keyboard for the lower notes, a clavichord could be used to practice organ repertoire . Most often, the addition of a pedal keyboard only involved connecting the keys of the pedalboard to the lower notes on the manual clavichord using string so the lower notes on the manual instrument could be operated by the feet . In the era of pipe organs, which used man - powered bellows that required several people to operate, and of churches only heated during church services if at all, organists used pedal harpsichords and pedal clavichords as practice instruments (see also: pedal piano). There is speculation that some works written for organ may have been intended for pedal clavichord . An interesting case is made by Speerstra (2004) that Bach's "Eight Little Preludes and Fugues", now thought spurious, may actually be authentic . The keyboard writing seems unsuited to organ, but Speerstra argues that they are idiomatic on the pedal clavichord . As Speerstra and Williams (2003) also note, the compass of the keyboard parts of Bach's six trio sonatas for organ (BWV 525--530) rarely go below the tenor C, so they could have been played on a single manual pedal clavichord, by moving the left hand down an octave, a customary practice in the 18th century . </P> <P> Much of the musical repertoire written for harpsichord and organ from the period circa 1400--1800 can be played on the clavichord; however, it does not have enough (unamplified) volume to participate in chamber music, with the possible exception of providing accompaniment to a soft baroque flute, recorder, or single singer . J.S. Bach's son Carl Philipp Emanuel Bach was a great proponent of the instrument, and most of his German contemporaries regarded it as a central keyboard instrument, for performing, teaching, composing and practicing . The fretting of a clavichord provides new problems for some repertoire, but scholarship suggests that these problems are not insurmountable in Bach's Well - Tempered Clavier (Loucks (1992)). Among recent clavichord recordings, those by Christopher Hogwood (The Secret Bach, The Secret Handel, and The Secret Mozart), break new ground . In his liner notes, Hogwood pointed out that these composers would typically have played the clavichord in the privacy of their homes . In England, the composer Herbert Howells (1892--1983) wrote two significant collections of pieces for clavichord (Lambert's Clavichord and Howells' Clavichord), and Stephen Dodgson (1924--2013) wrote two clavichord suites . </P>

The clavichord was a popular instrument for the home