Abstract: A musical instrument with two or more classes of pitches where at least one class is a diminished chord extended over an arbitrary number of octaves, and another class is another chord extended over the same span of octaves. The pitches of the second class of pitches are interlaced with the pitches of the diminished chord of the first class of pitches. Additional classes are chords similarly interlaced with other classes, with one class of any interlaced pair of classes being a diminished chord.

Abstract: A musical keyboard has keys arranged and marked for generating tones of a twelve-tone scale. A first register of keys generates first sets of six tones being whole tones apart in the twelve-tone scale. A second register of keys generates second sets of six tones being whole tones apart in the twelve-tone scale. The tones of each first set are disjoint and half-tones apart from the tones of each second set, and the tones of the first and second set correspond alternately to the twelve-tone scale. The keys on the first register are linearly arranged between the keys on the second register, and the keys on the second register are linearly arranged between the keys on the first register. The keys have markings arranged in units of three unique markings, and the units of three unique markings repeat identically and sequentially on the keys of the first and second registers.

Abstract: A musical keyboard has keys arranged and marked for generating tones of a twelve-tone scale. A first register of keys generates first sets of six tones being whole tones apart in the twelve-tone scale. A second register of keys generates second sets of six tones being whole tones apart in the twelve-tone scale. The tones of each first set are disjoint and half-tones apart from the tones of each second set, and the tones of the first and second set correspond alternately to the twelve-tone scale. The keys on the first register are linearly arranged between the keys on the second register, and the keys on the second register are linearly arranged between the keys on the first register. The keys have markings arranged in units of three unique markings, and the units of three unique markings repeat identically and sequentially on the keys of the first and second registers.

Abstract: An arrangement for pivotally securing a roof panel to the upper end of a housing frame, includes a plate fixedly secured to the upper end of a ceiling panel or wall panel of the housing frame; a rocker secured to the roof panel and positioned on the plate; and flexible hinge band wrapped and secured about the plate and rocker in a substantially figure eight configuration for permitting pivotal movement of the rocker on the plate along two different pivot axes to allow hyper extension or pivoting of the rocker beyond a final resting position.