Richard Dobson wrote:

> To bring this topic a little more into the Csound fold, perhaps there is a need
> for an opcode to reconfigure the cpspch calculations, for different scales?

Use cps2pch or cpsxpch.
All of the following is copied out of rasmus ekman's Windows help file for Csound:

icps    cps2pch    ipch, iequal
icps    cpsxpch    ipch, iequal, irepeat, ibase

Converts a pitch-class notation into cycles-per-second for equal divisions of the octave (for cps2pch) or for equal divisions of any interval. There is a restriction of no more
than 100 equal divisions.
See also Pitch converters.

INITIALISATION

ipch - Input number of the form 8ve.pc, indicating an octave' and which note in the octave.

iequal - if positive, the number of equal intervals into which the octave' is divided. Must be less than or equal to 100. If negative is the number of a table of frequency
multipliers

irepeat - Number indicating the interval which is the octave'. The integer 2 corresponds to octave divisions, 3 to a twelveth, 4 is two octaves, and so on. This need not be an
integer, but must be positive.

ibase - The frequency which corresponds to pitch 0.0

NOTES

1. The following are essentially the same

ia = cpspch(8.02)

ib cps2pch 8.02, 12
ic cpsxpch 8.02, 12, 2, 1.02197503906

2. These are opcodes, not functions.
3. Negative values of ipch are allowed, but not negative irepeat, iequal or ibase.

EXAMPLES

inote    cps2pch    p5, 19 ; convert oct.pch to cps in 19ET
inote    cpsxpch    p5, 12, 3, 261.62561 ; Pierce scale centered on middle A
inote    cpsxpch    p5, 21, 4, 16.35160062496 ; 10.5ET scale

The use of a table allows exotic scales by mapping frequencies in a table

For example the table

f2 0 16 -2 1 1.1 1.2 1.3 1.4 1.6 1.7 1.8 1.9

can be used with

ip cps2pch p4, -2

to get a 10 note scale of unequal divisions