Information:  - The Marxophone is a fretless zither with a system of metal hammers added for ease of playing . It features two octaves of double melody strings in the key of C major ( middle C to C '' ) , and four sets of chord strings ( C major , G major , F major , and D7 ) . Sounding somewhat like a mandolin , the Marxophone 's timbre is also reminiscent of various types of hammered dulcimers . The player typically strums the chords with the left hand . The right hand plays the melody strings by depressing spring steel strips that hold small lead hammers over the strings . A brief stab on a metal strip bounces the hammer off a string pair to produce a single note . Holding the strip down makes the hammer bounce on the double strings , which produces a mandolin - like tremolo . The bounce rate is somewhat fixed , as it is based on the spring steel strip length , hammer weight , and string tension -- but a player can increase the rate slightly by pressing higher on the strip , effectively moving its pivot point closer to the lead hammer . Numerically coded sheet music prepared specifically for the Marxophone indicates when and in what order to play melody and chord strings . This type of music , similar to tablature , was produced for those who could not read standard notation . A rectangular piece of metal provides a backstop for the spring steel hammers , displays the name Marxophone and the patent number , and has clips that hold sheet music . It also marks the 15 keys by letter ( C , D , etc. ) , by number ( 1 - 15 ) and in standard musical notation . When the instrument is moved or stored , the metal rectangle bends down , holding the keys against the strings , so the Marxophone can fit into its case -- which is the size of a large briefcase .  - A plectrum is a small flat tool used to pluck or strum a stringed instrument. For hand-held instruments such as guitars and mandolins, the plectrum is often called a pick, and is a separate tool held in the player's hand. In harpsichords, the plectra are attached to the jack mechanism.  - Music is an art form and cultural activity whose medium is sound and silence, which exist in time. The common elements of music are pitch (which governs melody and harmony), rhythm (and its associated concepts tempo, meter, and articulation), dynamics (loudness and softness), and the sonic qualities of timbre and texture (which are sometimes termed the "color" of a musical sound). Different styles or types of music may emphasize, de-emphasize or omit some of these elements. Music is performed with a vast range of instruments and vocal techniques ranging from singing to rapping; there are solely instrumental pieces, solely vocal pieces (such as songs without instrumental accompaniment) and pieces that combine singing and instruments. The word derives from Greek  ("mousike"; "art of the Muses"). In its most general form, the activities describing music as an art form include the production of works of music (songs, tunes, symphonies, and so on), the criticism of music, the study of the history of music, and the aesthetic examination of music. Ancient Greek and Indian philosophers defined music as tones ordered horizontally as melodies and vertically as harmonies. Common sayings such as "the harmony of the spheres" and "it is music to my ears" point to the notion that music is often ordered and pleasant to listen to. However, 20th-century composer John Cage thought that any sound can be music, saying, for example, "There is no noise, only sound."  - F major (or the key of F) is a major scale based on F, with the pitches F, G, A, B, C, D, and E. Its key signature has one flat, B.  - A soprano is a type of classical female singing voice and has the highest vocal range of all voice types. The soprano's vocal range (using scientific pitch notation) is from approximately middle C (C) = 261 Hz to "high A" (A) =880 Hz in choral music, or to "soprano C" (C, two octaves above middle C) =1046 Hz or higher in operatic music. In four-part chorale style harmony, the soprano takes the highest part, which usually encompasses the melody.  The soprano voice type is generally divided into the coloratura, soubrette, lyric, spinto, and dramatic soprano. The lyric soprano is the most common female singing voice.  - Mandobass is the largest (and least common) member of the mandolin family, sometimes used as the bass instrument in mandolin orchestras. It is so large that it usually isn't held in the lap, but supported on a spike which rests on the floor. The neck-scale length on a full-size mando-bass is similar to that of a standard orchestral double bass viol: about 43" (110 cm). The instrument is otherwise similar to the smaller, higher-pitched members of the mandolin family, having a fretted neck, a headstock with geared tuning machines, and a large resonating body oftenbut not alwaysshaped like that of other mandolins.  - Lute can refer generally to any string instrument having the strings running in a plane parallel to the sound table (in the HornbostelSachs system), more specifically to any plucked string instrument with a neck (either fretted or unfretted) and a deep round back, or more specifically to an instrument from the family of European lutes.  - In music, unison is two or more musical parts sounding the same pitch or at an octave interval, usually at the same time.  - C major (or the key of C) is a major scale based on C, with the pitches C, D, E, F, G, A, and B. Its key signature has no flats and no sharps.  - The harp is a stringed musical instrument which has a number of individual strings running at an angle to its soundboard, which are plucked with the fingers. Harps have been known since antiquity in Asia, Africa, and Europe, dating back at least as early as 3500 BC. The instrument had great popularity in Europe during the Middle Ages and Renaissance, where it evolved into a wide range of variants with new technologies, and was disseminated to Europe's colonies, finding particular popularity in Latin America. While some ancient members of the harp family died out in the Near East and South Asia, descendants of early harps are still played in Burma and in Sub-Saharan Africa, while other defunct variants in Europe and Asia have been revived by musicians in the modern era.  - The mandocello is a plucked string instrument of the mandolin family. It has eight strings in four paired courses, tuned in fifths like a mandolin, but is larger, and tuned CC-GG-dd-aa (low to high in pitch). It can be described as being to the mandolin what the cello is to the violin.  - G major (or the key of G) is a major scale based on G, with the pitches G, A, B, C, D, E, and F. Its key signature has one sharp, F.  - The mandola (US and Canada) or tenor mandola (Ireland and UK) is a fretted, stringed musical instrument. It is to the mandolin what the viola is to the violin: the four double courses of strings tuned in fifths to the same pitches as the viola (C-G-D-A low-to-high), a fifth lower than a mandolin. The mandola, although now rarer, is the ancestor of the mandolin, the name of which means simply "little mandola".  - The major scale or Ionian scale is one of the most commonly used musical scales, especially in Western music. It is one of the diatonic scales. Like many musical scales it is made up of seven notes: the eighth duplicates the first at double its frequency so that it is called a higher octave of the same note (from Latin "octavus", the eighth).  - In musical notation, a key signature is a set of sharp, flat, and rarely, natural symbols placed together on the staff. Key signatures are generally written immediately after the clef at the beginning of a line of musical notation, although they can appear in other parts of a score, notably after a double barline.  - The cello (; plural cellos or celli) or violoncello is a bowed string instrument with four strings tuned in perfect fifths. The strings from low to high are generally tuned to C, G, D and A, an octave lower than the viola. It is a member of the violin family of musical instruments, which also includes the violin and viola.  - A mandolin (; literally "small mandola") is a musical instrument in the lute family and is usually plucked with a plectrum or "pick". It commonly has four courses of doubled metal strings tuned in unison (8 strings), although five (10 strings) and six (12 strings) course versions also exist. The courses are normally tuned in a succession of perfect fifths. It is the soprano member of a family that includes the mandola, octave mandolin, mandocello and mandobass.  - The octave mandolin is a fretted string instrument with four pairs of strings tuned in fifths, G, D, A, E (low to high), an octave below a mandolin. It has a 20 to 23-inch scale length and its construction is similar to other instruments in the mandolin family. Usually the courses are all unison pairs but the lower two may sometimes be strung as octave pairs with the higher-pitched octave string on top so that it is hit before the thicker lower-pitched string. Alternate tunings of G, D, A, D and A, D, A, D are often employed by Celtic musicians.    Given the information, choose the subject and object entities that have the relation of 'subclass of'.
marxophone , plucked string instrument