Mellow, gentle, velvety, mild, sonorous, warm, smooth, picturesque, tense, active, penetrating, plaintive, long, light, delicate, full, round, slender, narrow, sensitive.
The U-shaped bend of the bassoon tube means that it lacks the penetrating and brilliant shawm-like sound of the oboe.
The bassoon’s timbre is rich in harmonics, which gives it particular color. The differences between the registers are very pronounced, which is one of the instrument’s most striking characteristics: full and sonorous in the lower register, slender, elegant and melodious in the middle and narrow and compressed in the upper register.
In all its registers, the notes of the bassoon – especially staccato notes – are well suited for the performance of humorous, comic effects and the depiction of musical caricatures.
Lower register: Bb1 – F2
The bassoon’s low notes with their substantial, compact and unobtrusive sound are often used as a bass foundation. They sound somewhat thicker and heavier than the higher notes and evoke a marked sense of serenity, peace and equanimity in pp passages.
In addition to this, composers have given them thematic tasks with a solemn, proud, dignified and majestic character.
Middle register: F#2 – Bb3
The notes in this register are those used most often on the bassoon, being ideally suited not only for tonal blends but also for solo work. The notes sound sonorous, rich, clear and stately. They are more intense than the low register and possess a wide range of expression; they can be gently caressing or sharply austere, merry and bright or melancholy and despondent. They are equally well suited for mysterious, demonic and eerie effects.
Upper register: B3 – Eb5
Because the high notes of the bassoon contain considerably fewer overtones than the low notes they do not possess the same clarity and are often felt to sound “squeezed” or “pressed” (though not shrill). This perception is reflected in countless passages in the literature in which the bassoons express apprehension, lamentation, distress, hardship, agony and fear.
The high notes also have a lyrical character, however, and can perform cantabile tasks.