Abstract: The invention provides an apparatus (10) adapted to teach wrist position of a non-bowing arm (2, 3, 4, 5, 6) in a pupil playing a stringed instrument, and a method of monitoring correct wrist position. The apparatus (10) comprises a non-contact proximity sensor (22), a proximity information transmitter (23); related circuitry (20), a power source (21) and, in one embodiment, a housing (11, 12). The housing is attachable to the stringed instrument in an operating position; and the non-contact proximity sensor (22) is positioned so that when the housing (11, 12) is in the operating position, the non-contact proximity sensor (22) is sensitive at least to when an inner part (8) of the wrist or hand of the pupil comes closer to the non-contact proximity sensor than a threshold distance (D) associated with misalignment of the hand (2) and forearm (3) of the pupil.

Abstract: A keyboard musical instrument learning aid having a plurality of keys including: sensing means operatively associated with the keyboard for sensing the presence of an object at a spaced disposition with respect to the keys of the keyboard; positioning means operatively associated with the sensing means for positioning the sensing means such that the spaced disposition is within a predetermined space with respect to the keys; and reporting means operatively associated with the sensing means and operable to report when an object is sensed to be present at the spaced disposition.

Abstract: A keyboard musical instrument learning aid having a plurality of keys including: sensing means operatively associated with the keyboard for sensing the presence of an object at a spaced disposition with respect to the keys of the keyboard; positioning means operatively associated with the sensing means for positioning the sensing means such that the spaced disposition is within a predetermined space with respect to the keys; and reporting means operatively associated with the sensing means and operable to report when an object is sensed to be present at the spaced disposition.

Abstract: A capillary writing medium colorant reservoir system for a writing instrument and process for producing the colorant reservoir. The main problem in such colorant reservoirs is the storage time. During this time, the writing capacity of new writing instruments declines since the walls of the writing instruments are, if only slightly, permeable to solvents. In the long run a stored writing instrument thus dries out and loses the major proportion of its original writing capacity. To this end, the invention has a colorant reservoir with an elongated reservoir body made of fibrous material. The reservoir body is surrounded by a sleeve which is permeable to liquids and gases and gives the reservoir body its shape. The reservoir stores colorant to produce liquid writing medium, the colorant being stored between the fibers of the fibrous material of the reservoir body in dry form. A single-part or multipart wick projects from either side of the reservoir body.

Abstract: A capillary writing medium colorant reservoir system for a writing instrument and process for producing the colorant reservoir. The main problem in such colorant reservoirs is the storage time. During this time, the writing capacity of new writing instruments declines since the walls of the writing instruments are, if only slightly, permeable to solvents. In the long run a stored writing instrument thus dries out and loses the major proportion of its original writing capacity. To this end, the invention has a colorant reservoir with an elongated reservoir body made of fibrous material. The reservoir body is surrounded by a sleeve which is permeable to liquids and gases and gives the reservoir body its shape. The reservoir stores colorant to produce liquid writing medium, the colorant being stored between the fibers of the fibrous material of the reservoir body in dry form. A single-part or multipart wick projects from either side of the reservoir body.