[pianotech] Treble agraffes and capo bar hardness

[jim at grandpianosolutions.com]

Recently there was some chat (which I can't locate) regarding hardness 
of capo bar terminations and shape of the bar.

As I remember, most of the chat was discussing the need for a hard(ened) 
bar accompanied by a not too aggressively shaped radius. As well as the 
value of the mass of the casting those bars are attached to was called 
out as useful.

Then I look at a brass agraffe treble...regular agraffes through the 
first treble section and upside down brass agraffes through  the high 
treble...brass thoughout, as in soft as a baby's tush. Termination radii 
by definition abrupt (because the agraffe head is not that wide), but 
not a sharp "V".  Presumably, the wire self-machines a slightly wider 
radius.

In trying to figure what I think about this capo bar hardness question, 
the first thing I try to do is ferret out unspoken assumptions which of 
course color the opinions.

For example, Ron Over's hard treble bar,accomanied by (from what I can 
gather) a high tension scale, quite stiff belly structure, not sure of 
hammer weight...targeting large venue projection?(not sure but from the 
Lilacs recording quite lovely)... Ed McMorrow's sharp shaping ( I think 
"V" with a 1mm bearing flat) in S&S plates, original non-hardened S&S 
casting, presumably reasonably soft, looking for self-machining by the 
wire,  accompanied by extremely light hammers, original S&S compression 
board, and vastly improved trebles (despite S&S customary treble 
weakness) into the high treble as well...Chickering's sweetness with the 
above mentioned soft brass agraffe setup.

So my question:  to what degree is the Capo termination hardness and 
shape targeting a specific tonal result, as opposed to adhering to 
geometrical necessity or limititations of allowable string abuse at the 
termination?

Jim Ialeggio

-- 
Jim Ialeggio
jim at grandpianosolutions.com
(978) 425-9026
Shirley, MA