The Sōjō scale
Sōjō uses the ryo scale. Its five core degrees are kyū G, shō A, kaku B, chi D, u E, with ei-kaku C and ei-u F as the two additional degrees. The characters on the tonic are played steadily at standard pitch, without meri.
Scale and characters by instrument
| Pitch | Jūniritsu | Role in this mode | Shō 笙 | Hichiriki 篳篥 | Ryūteki 竜笛 | Biwa 琵琶 | Koto 筝 |
|---|---|---|---|---|---|---|---|
| G | Sōjō 双調 | kyū (core), tonic | 十G5 | 舌G4丄G5 | 丄G5責丄G6 | 一G2str. 1, open乙G3str. 2, fret 3クG3str. 3, open也G4str. 4, fret 4 | 一G3三G4八G5巾G6 |
| A | Ōshiki 黄鐘 | shō (core) | 乞A4行A5 | 五A4丁A5 | 夕A5責夕A6 | 工A2str. 1, fret 1コA3str. 2, fret 4七A3str. 3, fret 1 | 四A4九A5 |
| B | Banshiki 盤渉 | kaku (core) | 一B4七B5 | 工B4 | 中B5責中B6 | 凢B2str. 1, fret 2ヒB3str. 3, fret 2 | 五B4十B5 |
| C | Shinsen 神仙 | ei-kaku | 比C6 | 凢C5 | 丅C6責丅C7 | フC3str. 1, fret 3〻C4str. 3, fret 3丄C4str. 4, open | — |
| D | Ichikotsu 壱越 | chi (core) | 凢D5上D6 | 六D5 | 六D6責六D7 | 斗D3str. 1, fret 4乚D3str. 2, open之D4str. 3, fret 4八D4str. 4, fret 1 | 二D4六D5斗D6 |
| E | Hyōjō 平調 | u (core) | 乙E5八E6 | 四E5 | 干,E5干E6責干E7 | 下E3str. 2, fret 1丨E4str. 4, fret 2 | 七E5為E6 |
| F | Shōzetsu 勝絶 | ei-u | — | — | — | — | — |
| G# | Fushō 鳧鐘 | outside the scale | 美G#5 | — | — | — | — |
| C# | Kamimu 上無 | outside the scale | 工C#5言C#6 | — | — | — | — |
| F# | Shimomu 下無 | outside the scale | 下F#5千F#6 | 一F#5 | 五F#5責五F#6 | 十F#3str. 2, fret 2ムF#4str. 4, fret 3 | — |
Pitches use international names (A4 = 430 Hz). Characters in red get a special technique such as meri or hakari in Sōjō (see the next table). Biwa entries show string and fret; koto entries are string names. The biwa and koto tunings are provisional, built from the mode's tonic and scale because no source was found. Shō pitches are for single pipes, not chords.
Special techniques in Sōjō (meri and hakari)
| Instrument | Character | Pitch (standard → this mode) | Technique (as played by the app) |
|---|---|---|---|
| Hichiriki | 舌 | G4 (unchanged) | When the line descends to it from 六, 四, it sinks about 50 cents at the join. |
| Hichiriki | 凢 | C5 (unchanged) | Meri-han: a shallow, relaxed embouchure gives C (Shinsen); the onset dips about 55 cents. |
| Ryūteki | 五 | F#5 (unchanged) | Tends to start sharp; pulled down about 18 cents to pitch. Held about 8 cents flat. Held for 1.5 s or more, falls about 35 cents: in steps mid-phrase, sliding at the end of a phrase. |
| Ryūteki | 夕 | A5 (unchanged) | Just before moving to 丄, 六, falls about 80 cents in steps. |
| Ryūteki | 丅 | C#6 → C6 | Lowered a semitone with hakari (half-covering the hole) and strong meri (also in 責). Tends to start sharp; pulled down about 30 cents to pitch. |
A cent is 1/100 of a semitone. The values are the app's defaults; change them in HICHIRIKI_MERI and RYUTEKI_MERI in gagaku/instruments.py and in gagaku/tunings.json.