Octave species various available intervals could be combined in any order, even restricting species to just the diatonic genus would result in twelve ways of dividing the octave (and his 17th-century editor, Marcus Meibom, pointed out that the actual number is 21), but "only seven species or forms are melodic and symphonic" . Those octave species that cannot be mapped onto the system are therefore rejected . In chant theory beginning in the 9th century, the "New Exposition" of the composite treatise called "Alia musica" developed an eightfold modal system from the seven diatonic octave species of ancient Greek theory, transmitted to
Seventh octave but some people who are capable of singing in the bass range (like singers Adam Lopez or Nicola Sedda) can do it. While notes in the sixth octave, between soprano high C and C7, can have enough color to sound flutey or canary-like, the squeaky, whistly tones in the seventh octave help give the whistle register its name, as do the piercing qualities of notes in this octave. Seventh octave The seventh octave is the highest octave of a piano. Using middle C (C4) as a guide, the next higher C is C5 or tenor C. The next C is