Sihu
Four strings, two pitch groups — one bow sounds both at once
Related
This page was supposed to open with a contradiction: the instrument is called "four-string huqin", yet some say it really has only two strings.
What the sources actually say is more interesting than a contradiction: the name is truthful — it really does have four strings. But the next layer is better: four strings, two pitches.
「四胡，因张 4 根弦故名」; 「1、3 弦为同度音，2、4 弦为同度音」
⭐⭐ Main line 56: one bow, two voices — "four" counts the strings, not the notes.
⭐⭐ How one bow sounds two pitches
This is the core of the page, and the part most often misunderstood.
It is not "four strings played separately". It does this:
「鬃弓分作两股夹入其间，同时拉响两组弦。」「弓毛的两股马尾分别穿过一、二弦和三、四弦的中间，弓子向外靠就是拉外弦，向内靠就是拉内弦。」
Picture it: the bow hair is split into two strands, one passing between strings 1 and 2, one between strings 3 and 4. Pull it and both groups speak.
⭐ That also explains its other alias, 「二夹弦」 — ⭐⭐ one bow clamping two string groups.
| The sihu | |
|---|---|
| Strings | four (four pegs) |
| ⭐ Actual pitches | ⭐ two (1·3 unison = outer; 2·4 unison = inner) |
| Between the groups | a perfect fifth (some sources say a fourth or a fifth) |
| ⭐ The bow | ⭐ hair split in two, sounding both groups at once |
⭐⭐ Why three tunings? Because the tuning gives way to the voice
The four strings split into an outer pair (1·3) and an inner pair (2·4), a perfect fifth apart. But different places tune it differently:
| Name | Outer | Inner | Used for |
|---|---|---|---|
| Mongolian high-pitched sihu | a¹ | d² | Mongolian music, higher |
| Er ren tai sihu (Inner Mongolia) | g¹ | c² | accompanying er ren tai |
| Mongolian mid-range sihu | #f¹ | b¹ | old artists' own singing in "silk-string seated singing" |
⭐⭐ Why? The research literature is unusually direct:
they 「在定弦 · 演奏时主要考虑嗓音的高度…… 乐器演奏都是为了演唱的便捷而服务。」
- Er ren tai: tuned g¹–c² because, in the interview,「考虑演员好唱，嗓子不费劲」;
- later changed because a local folk arts troupe wanted「提高音量 · 音高」;
- the mid-range sihu sits lower because those singers'「嗓音都不是很高，为了好唱」.
⭐⭐ This is the most important line on the page. A tuning is not a property of the instrument — it is a property of the human voice. This is the same thread as the zhuihu "staying close to the singing voice" and the yehu "dropping an octave to take the supporting part": across this whole bowed-string section, the pitch of these instruments is repeatedly decided by a sung line.
四胡属拉弦弦鸣乐器（弓擦 · 四弦 · 四轴）。四根弦分为两组：第 1·3 弦同度为外弦，第 2·4 弦同度为内弦，两组之间为纯五度。⚠️ 各路定弦不同：蒙古高音四胡 a¹–d² · 二人台四胡 g¹–c² · 蒙古中音四胡 #f¹–b¹。本图按二人台四胡取 G4–D5 示意；组内两弦同度，故实际发两个音。记谱即实音。
⭐⭐ "Pinging" and "stopping": two hands, one instrument
Besides the stopping technique both Mongolian and Han players use, older Mongolian artists use a special "top-string" technique — and this has fed back into the instrument's shape:
the differences in the instrument's form「源于这一技法差异」— 「蒙古四胡的琴弦离琴杆的距离远，而二人台四胡则不需要」, and that distance「影响了琴轴的变化以及琴码的位置」.
⭐⭐ The same pattern again: how the hand works decides how the instrument is made. (The yehu's coconut shell gained a foot because it was unstable; here, the fingering decides the distance from string to neck.)
⭐⭐ Three names, three languages
| Name | Source | Named after |
|---|---|---|
| 四胡 | Chinese usage | ⭐ four strings |
| 四股子 · 二夹弦 | Chinese aliases | ⭐ four strands · ⭐⭐ "two-clamped strings" |
| 胡尔 · 朝勒 · 四弦 | Mongolian | the Mongolian name |
| 提琴 | 《律吕正义后编》 | a refined term in a Qing music-treatise |
| 奚琴 | ancient | ⭐ its ancestor; the sihu descends from the xiqin |
⭐⭐ The three names point to three different worlds: 「四胡」 counts strings, 「胡尔·朝勒」 is Mongolian, 「提琴」 is the Qing court's scholarly renaming. An instrument with three names belongs to two linguistic traditions at once — that says more about it than the string count.
Form: "slightly longer and thicker" than the erhu
「形制与二胡相同，琴杆用红木或乌木制，略长而粗，置四轴，琴头平顶无饰，琴筒为木制，有圆筒形 · 六角形 · 八角形之分，一端蒙以羊皮或蟒皮。」
⭐⭐ "Slightly longer and thicker" is the fingerprint of the four-string requirement: two extra groups need a thicker neck for four pegs, and a longer neck and body for two unison pairs to resonate. The same logic as the gehu, which lay horizontal to supply the bass — form is forced by what the instrument has to do.
⚠️ One honest uncertainty on this page: the bow length differs across sources — one gives 「琴弓长 75 厘米」 with the hair split in two, another gives 60 cm. ⭐ This page deliberately does not pick one figure: both may describe different forms or different measuring conventions.
⭐⭐ An accompaniment list spanning half the country
Narrative singing: Jingyun dagu, Xihe dagu, Tianjin shidiao, Hubei xiaoqu, Shaoxing lianhualuo. Opera and puppetry: er ren tai (with dizi and yangqin, plus clappers and wooden blocks for rhythm), quju, pishadow.
Where: 「流行于蒙古国东部与中国内蒙古 · 东北和华北各省、区」.
⭐⭐ Why can a grassland bowed instrument accompany genres from Beijing to Shaoxing to Hubei? ⭐ Because it is a walking instrument — travelling singers take it wherever they sing.
Heritage: er ren tai, first national list (2006)
Er ren tai is named for the fact that all of its content is「两人对歌对舞」, and it is
accompanied by dizi, sihu and yangqin; er ren tai was listed in 2006 in China's first batch of national intangible cultural heritage.
⭐⭐ That completes the name story: the instrument belongs not only to the Mongolian tradition but also lives inside er ren tai and Jingyun dagu — a name that carries a people and a travelling singing style at once.
| Class | Assignment |
|---|---|
| HS class | Chordophone · bowed (friction with a bow) · with definite pitch |
| Sub-type | bowed (wooden sound box, round / hexagonal / octagonal · sheep or python skin at one end · neck of redwood or ebony, longer and thicker than the erhu · four pegs · flat undecorated head) · four strings in two unison pairs · the bow hair split in two, sounding both groups at once · the two groups a perfect fifth apart |
| Family | China · bowed strings (descends from the ancient xiqin · shared by the Mongolian and Han peoples · three sets of tunings across different song traditions) |
| Bayin | silk |
Recap in one table
| Q | A |
|---|---|
| ⭐ The key point | ⭐⭐ four strings, two pitches, one bow（1·3 unison = outer · 2·4 unison = inner; the hair splits in two） |
| The truth about the name | named for four strings — "four" counts strings, not notes |
| Another alias | 「二夹弦」— one bow clamping two groups |
| Three names | 四胡 (strings) · 胡尔·朝勒 (Mongolian) ·「提琴」(Qing treatise) |
| Form | as the erhu but longer and thicker · four pegs · round / hexagonal / octagonal body · sheep or python skin |
| ⭐ Tuning | ⭐⭐ three: a¹–d² · g¹–c² · #f¹–b¹ — all because「为了演唱的便捷而服务」 |
| Technique | top-string（Mongolian）and stopping; technique even shapes the form |
| Accompaniment | Jingyun dagu, Xihe dagu, Tianjin shidiao, Hubei xiaoqu, Shaoxing lianhualuo, er ren tai, quju, pishadow |
| Repertoire | ⭐ 《Gànlù》 · 《Bāyīn》 · 《Mòdélìémǎ》 |
| Bayin | silk |
The previous page showed the yehu dropping an octave to take the supporting part; this page shows the zhuihu and the yehu's recurring point turning into three different tunings — ⭐⭐ across this whole bowed-string section, the same idea keeps returning: the pitch of an instrument is decided by a sung line.
Listen in the library
All tracks from midicn-lib — inline badge is the license tier (C1 commercial / C2 non-commercial / C3 study only).
Sources
- ⭐⭐ 名字与"矛盾"（本批第 56 条主线：一把弓，两个声部）：「四胡，因张 4 根弦故名，亦称作四股子 · 二夹弦」；⚠️ 但四根弦只发两个音：「其中 1、3 弦为同度音，2、4 弦为同度音，两组弦以四或五度定弦」—— ⭐⭐ 名字没撒谎（确实是四根弦），但"四"和"音"是两回事
- ⭐⭐ 一把弓两股毛（本页最该记住的一条）：「鬃弓分作两股夹入其间，同时拉响两组弦」；「弓毛的两股马尾分别穿过一、二弦和三、四弦的中间，弓子向外靠就是拉外弦，向内靠就是拉内弦」—— ⭐⭐ 这不是"四根弦各拉各的"，而是一支弓同时出声
- ⭐ 弓长有出入：「琴弓长 75 厘米、马尾分成两股」（另一来源记 60 厘米）—— ⚠️ 各家数据有出入，本页不硬取单一数字
- ⭐⭐ 形制（与二胡同源而加粗加长）：「源于古代奚琴，蒙古族称其为胡尔 · 朝勒或四弦，《律吕正义后编》则称之『提琴』」；形制「与二胡相同，琴杆用红木或乌木制，略长而粗，置四轴，琴头平顶无饰，琴筒为木制，有圆筒形 · 六角形 · 八角形之分，一端蒙以羊皮或蟒皮」
- ⭐⭐ 定弦（三种，与嗓音有关——本页最实用的一段）：四胡分四根弦为外弦（1·3 同度）与内弦（2·4 同度），里外音程关系为纯五度；蒙古高音四胡定弦外弦 a¹ · 内弦 d²；二人台四胡定弦外弦 g¹ · 内弦 c²；蒙古中音四胡（老艺人"丝弦坐唱"用）外弦 #f¹ · 内弦 b¹；⭐ 「定弦 … 主要考虑嗓音的高度 … 都是为了演唱的便捷而服务」
- ⭐⭐ "顶弦"与"按弦"两种技法：蒙汉艺人在"按弦"之外，蒙古族老艺人会使用一种「顶弦」的特殊技法；⚠️ 形制差异（蒙古四胡琴弦离琴杆距离远，二人台四胡不需要）源于这一技法差异（影响琴轴变化与琴码位置）
- ⭐⭐ 地域分布（一件"走路"的乐器）：四胡「流行于蒙古国东部与中国内蒙古 · 东北和华北各省、区」；⚠️ 属地按来源原样记录
- ⭐⭐ 伴奏对象（跨度极大）：为京韵大鼓 · 西河大鼓 · 天津时调 · 湖北小曲 · 绍兴莲花落等说唱，以及二人台 · 曲剧 · 皮影等戏曲伴奏
- ⭐⭐ 蒙古族与汉族共同乐器：四胡「源于古代奚琴，乃蒙古族和汉族的共同乐器」；亦为「二人台」的主要伴奏乐器之一（与笛子 · 扬琴并列，另辅以梆子与四块瓦）
- ⭐ 代表曲目：《赶路》 · 《八音》 · 《莫德列马》
- ⭐ 二人台与长调（非遗背景）：二人台「因演出内容皆以两人对歌对舞而命名」，主要伴奏乐器包括笛子 · 四胡 · 扬琴，另辅以梆子和四块瓦等敲击乐器以加强节奏感；2006 年被列入中国第一批《国家级非物质文化遗产名录》依中国香港康乐及文化事务署「民族音乐巡迴展览·内蒙古篇」资料
- ⚠️ 别名与族源提醒：「四胡」虽名含"胡"，但其蒙古语名为胡尔 · 朝勒，而汉语旧籍《律吕正义后编》称之为「提琴」—— ⭐ 三套名字并存，本身就是"这件乐器跨越两种语言传统"的证据
- 「四胡属八音中的丝」依通行资料
Used for fact-checking only; all prose is original.