The struggle to explain the universe.

What a waste of my precious four minutes. (Not that I watched all of it.)

Array of notes, arranged to a certain sequence of tones after a starting key, to give a certain harmony.

See:

Minor Scale
Major Scale

Certain sequence of notes in a musical scale.

Consecutive playing of notes in a chord continuously, usually as background to instrumental or vocal solo.

A tool to generate arpeggios with chosen style and variations, using the notes in selected chord.

A move in chess, where player puts her king behind one of her rooks. There are two variations, namely castle-king-side and castle-queen-side; which are quite sufficiently self-explanatory.

A tactic in chess, where one piece threatens two of the opponent pieces at the same move.

A situation/tactic in chess, where a less valued piece is caught in between a higher valued piece or its own king and a threatening opponent piece; prohibiting it to move without losing the higher valued piece (or denying altogether in case of king).

A strategic board game, played on a 64 square board, with 32 pieces (16 each) with different behaviours and capabilities. Said to be one of the oldest games of the world.