|
JPS5319872A
|
|
Visual metronome
|
|
CA1079521A
|
|
Optical metronome
|
|
US4082029A
|
|
Optical metronomes
|
|
US4061072A
|
|
Device to identify chords on a keyboard instrument and key mechanism for use therewith
|
|
US4037511A
|
|
Teaching device for attachment to an organ
|
|
CA1043141A
|
|
Apparatus for use when playing a stringed instrument
|
|
US4030400A
|
|
Chord playing attachment for a stringed instrument
|
|
CA1059756A
|
|
Optical metronome
|
|
US3996833A
|
|
Optical metronome
|
|
US3945292A
|
|
Optical metronome
|
|
US3942404A
|
|
Optical metronome with transparent sheet music
|
|
US3916159A
|
|
Record sheet or card having raised portions with guiding means
|
|
CA961318A
|
|
Teaching device for attachment to a keyboard instrument
|
|
US3886839A
|
|
Optical metronome
|
