source file: m1439.txt
Date: Sat, 6 Jun 1998 08:53:00 -0700

Subject: 9:8 and 10:9 on the pedal steel

From: "Bob Lee" <quasar@wco.com>

Paul Erlich wrote:
> If one really hears intervals at the 9-limit or higher, then both 9:8
> and 10:9 must be considered consonant, and there should be a dissonant
> point about halfway between them.

then Graham Breed wrote:
> Granted, the 9/8 isn't "clearly evoked" but it can still function
> as a 9-limit consonance.  Besides, how do the other ratios
> support 10/9?

Now, this is a little aside of the conversation, but aren't 9:8 and 10:9
both part of the 5-limit system?  Partch includes them in his 5-limit
chapter in "Genesis".  Where does this "9-limit" talk come from?  9 isn't a
prime number.

Both 9:8 and 10:9 are used in the standard E9th pedal steel.  Typically the
F# is tuned to 9:8 and lowered to 10:9 with the pedal that raises the B
(3:2) to C# (5:3).  I've always thought of it as a 5-limit system.  There's
nothing here to really challenge the ear.

The interval between 10:9 and 9:8 is significant (about 22 cents).  It's
worth noting that some amateur steel players try to split the difference
instead of tuning the F# string JI and adding a tuning rod for the change
from 9:8 to 10:9.  The success of that approach depends on the amount of
"cabinet drop" of the individual instrument.  When you engage a pedal, the
increased stress on the instruments tends to detune strings that aren't
attached to the pedal.

On some inferior instruments, cabinet drop detuning can be as much as 10
cents!  So, if our amateur steel player tunes his 9:8 F# 6 cents flat, and
gets 10 cents of cabinet drop when he engages the pedals (and moves the bar
up a 10th of a fret to compensate for it, we hope), his 10:9 will be 6 cents
sharp.  This is "close enough for country", as they say...

    -b0b-

http://wco.com/~quasar/articles/just_e9.html