The T100 scale by M. Welte & Söhne (Freiburg) was the first reproduction system of its kind and caused a sensation in 1904/1905 that was unlike any other in the world. 80 notes are played, 20 holes are used for the complex intonation control. "Red" or "green" was derived from the characteristic colour of the music roll paper - this was mostly red for the T100 rolls - and mostly green for the T98 rolls. However, rolls of the other format were also produced in other paper colours.

The allocation of the 100 holes of the Welte T100 (red) scale is:

Hole 1: Bass mezzoforte from

Hole two: Bass Mezzoforte on

Hole 3: Bass Crescendo piano

Hole 4: Bass crescendo forte

Hole 5: Bass Sforzando Piano 

Hole 6: Bass Sforzando Forte

Hole 7: Piano pedal (left pedal) off

Hole 8: Piano pedal (left pedal) on

Hole 9: resistance high (less suction air supply)

Hole 10: resistance small (more suction air supply)

Hole 11-90: 80 notes from C1 to g4

Hole 91: Return

Hole 92: without allocation

Hole 93: Fortepedal (right pedal) on

Hole 94: Fortepedal (right pedal) off

Hole 95: Sforzando Forte treble

Hole 96: treble Sforzando Piano

Hole 97: treble crescendo forte

Hole 98: treble crescendo piano

Hole 99: treble mezzoforte in

Hole 100: treble mezzoforte from

Most of the pictures were taken for the Welte red system - for the Welte green scale, which was only introduced in 1924, the existing Welte T100 (red) pictures were recoded into the smaller roll format and re-punched.