Bright timbres stem from strong energy in harmonics above the seventh

Evidence

Notes excluding the seventh harmonic sound considerably less “reedy” than those with it; the seventh harmonic is one of the lowest that is not resolved by the hearing system (provided the sixth and/or eighth are/is also present). … The clarinet has a particular timbre of its own due to the dominance of the odd harmonics in its output, and it is often described as being “nasal.” — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1478 (#exemplifies, via linked claim)

Categorization

• corroborated: 2 independent passages support this claim
• XREF: connects to: Instrument timbre differences stem from harmonic spectra that shape masking breadth — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 449; Most acoustics texts attribute trumpet brilliance to treble boost; Harder blowing grows higher harmonics and brightens or rasps wind-instrument tone. (+10 more)

Broader Connections

• Dark or dull timbres lack energy in harmonics above the seventh #qualifies (0.95)
• The unresolved seventh harmonic imparts reedy timbre to instruments like the clarinet #exemplifies (0.80) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1478
• Even harmonics in clarinet tones are suppressed but not absent from the spectrum #expands (0.80)
• Nonlinear distortion generates new frequencies that change timbre with volume #expands (0.75)
• Pipe organ stops can reinforce non-octave harmonics to reshape timbre #expands (0.75)