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Figured BassChord VoicingRegisterTimbreLuteHarpsichordViolRacketHarp

The theorbo is a lute with an absurdly long neck. It is not "a bigger lute" — the extra half of that neck carries a whole set of extra-long bass strings whose only job is to hold up the lowest layer of a 17th-century ensemble.

It asks the same question as the racket, and gives the mirror-image answer:

⚠️ Two ways to make an instrument sound low Pitch is set by how long the vibrating body is — a tube or a string alike. So there are only two roads to a bass register: | Road | Method | Examples | |---|---|---| | Lengthen | make the vibrating body long and find a way to carry it | theorbo (longer strings) · harp (strings lengthened step by step) | | Fold | fold an already long body | racket (a folded bore) · bassoon | The racket said "the tube is too long → fold it"; the theorbo says "the strings must be long → let them be long". One physical constraint, two opposite craft answers.

It solves an ensemble problem. Seventeenth-century music often has a single bass line (the continuo), over which a plucked or keyboard instrument improvises chords. Keyboards (harpsichord · organ) can cover the harmony, but a plucked bass has more core and more agility — so the theorbo became a regular in that chair.

Structure: two necks, two pegboxes

Three points:

1. Two neck sections, two pegboxes — its most recognisable feature. The first section has a fingerboard and can be stopped; beyond the first pegbox the rest of the neck has no fingerboard, so those strings can only be played open, and they exist purely for the bass. 2. The bass comes from length, not thickness. A thicker string does lower the pitch, but it sounds muddy and responds slowly; lengthening keeps the low notes clear and grainy. That is the real design choice. 3. Commonly about 14 single strings (6 stopped + 8 long bass strings), though configurations vary a great deal by period and region, from the low teens upward.

The price: re-entrant tuning

This figure shows its most counter-intuitive fact: the neck was lengthened for the bass, but that same length also lengthens the top two courses — at equal tension a thin string tuned to its normal pitch would break, so they are tuned an octave lower.

So the tuning has a "kink": course 1, which looks highest by position, is not above course 3. This is called re-entrant tuning.

This is exactly the kind of fact the site wants remembered: no part of an instrument is free — the long neck buys a bass, and the price is the top two courses' register.

Range

西奥伯琴属弦鸣乐器（拨弦）。约 E2–A4；最低几个音由只弹空弦的延长低音弦提供，按弦段只覆盖中高音区。不同形制与调弦差别较大，弦数与最低音各不相同。记谱即实音。

• About E2–A4, and note that the stopped section covers only the upper middle: the lowest notes can only be open strings.
• The bass cannot be fingered, which dictates how music is written for it: low notes come in columns, layer by layer, not as free-moving melodic lines.
• Working register E2–A3 — its home ground is the bass and the harmonic skeleton.

Timbre, and how to hear it

Four cues:

1. A bass with core. Grainier and more defined than a keyboard's — every note has a clear onset. 2. Fast decay. A plucked note starts falling the instant it sounds, so it supplies rhythmic bass — layer pushing on layer — rather than a sustained pad. 3. The upper register can sound bare. Re-entrant tuning spaces chords differently from what you expect, so the middle-high register sounds sparser than you would guess. 4. It is also a rhythm instrument. In a continuo group the plucked instrument often carries the pulse's skeleton.

Playing techniques

• The left hand only works the stopped section. The long bass strings are out of reach — their only states are plucked or not, so the bass is a fixed set of notes.
• The right hand crosses a long distance, travelling between the stopped section and the extension near the far end — very different technique from an ordinary lute.
• A strap is usual, and the body is held slanted. The instrument is too long to manage on the knee.
• Continuo means reading numbers. Figures (6, 4, 7…) under the bass line tell the player what to improvise — this is figured bass in live operation.
• It is not a virtuoso solo vehicle. Solo music exists, but its ensemble value lies in accompaniment.

The family

Set beside the previous entry, the two threads of this group are complete:

There is no third, free option.

History

It left the stage not because of the instrument but because of a change in how ensembles were staffed: once the bass line was carried by keyboard plus cello/double bass, an instrument built specifically for figured bass had nowhere to sit. It was not beaten by a better instrument; it was beaten by a new division of labour.

Common misconceptions

• "It is a big guitar / big lute." The key difference is two neck sections and two pegboxes — that extra half is not decoration, it carries a set of open bass strings.
• "More strings means a higher range." The extra strings are added downwards; and the top of the range was actually tuned an octave down because the neck grew.
• "Tuning always runs low to high." It is re-entrant: string 1 is not above string 3.
• "It only plays bass notes." It fills in chords and often melodic inner parts; the bass is simply the layer it cannot be replaced on.
• "The long neck is arbitrary." Every centimetre serves the bass strings, and the price is the register of the top two courses.
• "It has nothing to do with the racket." Two realisations of one principle: lengthen the vibrating body, or fold it.

Next

The first entry on the "strings" thread ends here: lengthen, buy a bass, pay with size and top register. The next instrument changes the question to weight: the portative organ has to carry a whole organ on someone's back. It asks the same thing from the other side: to make an instrument portable, what will you give up? :::

Sources

• 结构依通行乐器资料：琴体 + 两段颈；指板只覆盖第一段，第二段延伸出去并在末端装第二个弦栓箱，专门挂延长的低音弦（只弹空弦）
• 「西奥伯琴属弦鸣乐器」依 Hornbostel–Sachs 分类；常见形制约 14 根单弦（6 根按弦 + 8 根延长低音弦），不同形制更多
• 「音域约 E2–A4，视形制与调弦而定」依通行乐器资料
• 「① ② 两个弦组被调低一个八度，形成回归式定弦；通行解释是颈加长后，同样张力下细弦按原音高会断」依乐器史与制琴通识
• 「17 世纪通奏低音的主要拨弦乐器之一，与羽管键琴 · 管风琴 · 低音维奥尔同组」依乐器史

Used for fact-checking only; all prose is original.