Time Signature A time signature is a device which shows how to count the time patterns in any bar. It is represented by either two numbers, a 'c', or 'c' with a vertical line through it. This is usually shown at the beginning of staves. These symbols give the number of beats to a bar.
Concerning the two numbers, the lower number represents the unit of time: it is written according to its value in terms of a semibreve. The number of top of a time-signature shows how many units there are to the bar.
The time signature is written on the stave just before the first note of the tune. A time signature with four quarter notes to the bar is written 4/4 (common time, also represented by a 'C'). The time signature for songs with two quarter notes to the bar is written 2/4, etc.
Key Signatures A grouping of sharp or flat signs placed immediately after the clef on the lines of the staff. Unless contradicted (cancelled) by natural signs, they affect every note with the same name as the ones marked.
Accidental any sharp, flat, or natural that is not given in the key signature. An accidental in front of a note applies as often as the note is repeated at that particular octave during the remainder of the bar it is in. In the bar that comes after accidental sharps or flats is usual to find 'warning' to contradict the accidentals in the previous bar.
Ad Libitum / Ad Lib. a tune meant to be sung or played very freely, without any regular pulse. They are written without any time signature or bar lines. The word 'freely' can be written Ad Libitum (or Ad lib.) meaning 'at will'.
The style and speed of the music is left for the player or singer to decide.
Bar Lines / Measure Lines Bar lines divide music in bars. Each bar has the number of beats indicated by the Time Signature. The first beat after the Bar-Line is usually the strongest beat in the Bar. (see double bar line)
Compound Time signatures with a dotted note beat. In simple time the beat is divided into two. In compound time the beat is divided into three.
Dotted notes Whatever the time signature may be, a dot after any note always makes it half as long again.
Double Bar Line A double bar line are two vertical lines that marks the end of a piece of music, or the end of a repeat. It can also mark the end of a section of music, a change of key or a change of time signature.
Flat Sign A flat sign (b) lowers or 'flattens' a note. It affects all notes in the same position which follow in the bar. Written immediately after the clef, it is part of the key signature.
Sharp Sign A sharp sign (#) raises or 'sharpens' a note. It affects all notes in the same position which follow in the bar. Written immediately after the clef , it is a part of the key signature .
