Syntagma Musicum. Three sizes of instruments could be used to play four-part music by doubling the middle size, e.g. F3–C4–C4–G4, or play six-part music by doubling the upper size and tripling the middle size, e.g. F3–C4–C4–C4–G4–G4. Modern nomenclature for such recorders refers to the instruments' relationship to the other members of consort, rather than their absolute pitch, which may vary. The instruments from lowest to highest are called "great bass", "bass", "basset", "tenor", "alto", and "soprano". Potential sizes include: great bass in F2; bass in B2 or C3; basset in F3 or G3; tenor in C4 or D4; alto in F4, G4 or A4; and soprano in C5 or D5. The alto in F4 is the standard recorder of the Baroque, although there is a small repertoire written for other sizes. In seventeenth-century England, smaller recorders were named for their relationship to the alto and notated as transposing instruments with respect to it: third flute (A4), fifth flute (soprano; C5), sixth flute (D5), and octave flute (sopranino; F5). The term flute du quart, or fourth flute (B4), was used by Charles Dieupart, although curiously he treated it as a transposing instrument in relation to the soprano rather than the alto. In Germanic countries, the equivalent of the same term, Quartflöte, was applied both to the tenor in C4, the interval being measured down from the alto in F4, and to a recorder in C5 (soprano), the interval of a fourth apparently being measured up from an alto in G4. Recorder parts in the Baroque were typically notated using the treble clef, although they may also be notated in French violin clef (G clef on the bottom line of the staff). In modern usage, recorders not in C or F are alternatively referred to using the name of the closest instrument in C or F, followed by the lowest note. For example, a recorder with lowest note G4 may be known as a G-alto or alto in G, a recorder with lowest note D5 (also "sixth flute") as a D-soprano or soprano in D, and a recorder in G3 as a G-bass or G-basset. This usage is not totally consistent. Notably, the baroque recorder in D4 is not commonly referred to as a D-tenor nor a D-alto; it is most commonly referred to using the historical name "voice flute". Structure Materials Recorders have historically been constructed from hardwoods and ivory, sometimes