Cobs

20-Note Cobs


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Tuning Scales

Roller Organs were not tuned to standard pitch, so there is great variation. A scale beginning on D will allow D, G, A, C, and E major chords and D, G, and A scales, so it is well-suited to play in the key of D or G. The mean temperament tuning1) allows it to play in almost perfect harmony.

  • 20-Note Scale:
    • D G A B (middle)C C# D E F# G G# A B C C# D E F# G A 2)
    • B E F# G# A A# B C# D# E F F# G# A A# B C# D# E F# 3)
    • C# F# G# A# B (middle)C C# D# F F# G G# A# B C C# D# F F# G# 4)
    • D# G# A# C C# D D# F G G# A A# C C# D D# F G G# A# 5)
1) Mean temperament was used prior to 1908 (approximately). At that time the Autophone Company switched to equal temperament because the reed sets were slightly less expensive.
2) most Gems after 1888, some Concerts after 1908
3) most Concerts before 1908
4) some Gems after 1908, some Concerts after 1908
5) most Gems before 1888
 
 
 

Todd Augsburger's Roller Organ Website