are 23 inches long, and each chord takes up 4 holes. The chord harmonica is used to provide chordal and rhythmic backing in an ensemble, much as rhythm guitar might do. Jerry Murad's Harmonicat's 1947 "Peg O' My Heart" was played on a Chord, with a cleverly arranged sequence of chords that produced the impression of a melody. Hohner's main Chord is known as the Hohner 48, because it plays 48 chords. Hohner from the 1930s to the late 1960s also produced the Polyphonia No. 8, which played 36 blow-only chords, in three rows. The concept failed and is often frowned upon by professional 48 chord players. Polyphonia and Chromatica Another form of harmonica is the Chromatica and Polyphonia harmonica. Basically identical in design, the Polyphonia (often shortened to "Poly") and Chromatica harmonicas have all notes in a row in chromatic scale, side by side. 150th anniversary and beyond For Hohner's 150th anniversary in 2007, the company began manufacturing Limited Edition Diatonic harmonicas all tuned to the key of C major only. Gold limited to 150 pieces. Chrome limited to 1,857 pieces. Standard Edition The "Gold Edition" harmonica is based upon the MS reed plates. It features a crystal glass comb and engraved gold-plated cover plates. The bottom cover plate has the serial numbers from 1 to 150. It is packaged in a leather case with an anniversary booklet. The "Chrome Edition" harmonica is also based upon the MS reed plates. Featuring a crystal glass comb and specially engraved chrome-plated anniversary cover plates. The bottom cover plate has the serial numbers from 1 to 1857. It is also packaged with an anniversary booklet. The "Standard Edition" model features a clear acrylic comb and the top cover plate is specially engraved. The "Standard Edition" model is presented in 12 piece wooden anniversary boxes. Artist series harmonicas Hohner has several harmonicas designed by several famous harmonica players. Larry Adler Classical harmonica player Larry Adler had his own harmonica series, still produced by the company, which were chromatic with either 12 or 16 holes. Toots Thielemans Jazz player Toots Thielemans also has a chromatic harmonica line with two types being Mellow Tone (for classical material) and Hard Bopper (for contemporary material). Stevie Wonder Stevie Wonder, plays both Hohner the 64 Chromonica and Super 64 with four-octave range on all his records since the 1960s. Steven Tyler Aerosmith's front man Steven Tyler has two