Roland AT-75 Electronic Keyboard User Manual


 
29
Selecting and Playing Sounds
Selecting and Playing Sounds
What’s the feet?
“Feet” is a term that began as a measurement of the length of the pipes
in a pipe organ.
The pipes that produce the basic pitch (fundamental) for each note are
considered to be “8 feet” in length.
Therefore, a pipe producing a pitch one octave below that of the
reference of 8' (eight feet) would be 16'; for one octave above the
reference, the pipe would be 4', and to take the pitch up yet another
octave it would be shortened to 2'.
The pitches of the harmonic bars are related as follows.
On tonewheel organs, the high-pitched footage for a portion of the high
range, and the low-pitched footage for a portion of the low range are
“folded-back” in units of one octave.
Folding back the high-frequency portion prevents the high-frequency
sounds from being unpleasantly shrill, and folding back the low-
frequency portion prevents the sound from becoming “muddy.”
On the ATELIER faithfully simulates this characteristic.
16' 8' 4' 2' 1'5
1
/
3
'2
2
/
3
'1
3
/
5
'1
1
/
3
'
one octave
below
5th root 8th 12th
15th
17th 19th 22nd
8' =
When the middle C (C4) note is pressed, each
harmonic bar will sound the following notes.
AT-75_e.book 29 ページ 2008年8月21日 木曜日 午前10時9分