Definition: Tempo is the speed of the beat.
Tempo is Italian for 'time', plural = tempi
Taken from: Unit 1, p.10
Definition: One of the most frequent and satisfying phrase structures consists of a first section, a contrasting section and a return to the initial section. This structure is known as either ABA or ternary form. It is found in many 19th Century piano pieces and 18th Century Minuets.
'This is a so-called ternary form because it is divided into three clearly defined sections'
Examples: Scherzo - Trio - Scherzo or Minuet - Trio - Minuet (popular in the 18th Century)
See also: Binary form
Taken from: Unit 14, p.16, Unit 9, p.12 and Unit 10, P.41 - 43
Definition: Tessitura is a useful word, referring to the general 'lie' of a vocal, or sometimes instrumental part : high, medium or low in its general range, for example. In Italian the word actually means 'texture', something rather different of course.
Taken from: Unit 14, p.12
Definition: A theme is a recognizable and recurrent series of notes. It may or may not sound complete in itself, since it frequently forms part of a larger structure.
A theme often consists of several repetitions of one or more motifs, and is not always complete in itself. None the less it will be a major component of a piece and will be repeated in a recognizable form several times, alternating with different material.
See also: Melody and Motif
Taken from: Unit 4, p.24 and Unit 16, p.70
Definition: A tie ties together the rhythmic values of two or more adjacent notes of the same pitch. Rests cannot be tied.
or 
Taken from: Unit 1, p.19
Tierce de Picardie (Picardy third)
Definition: ... feature is called a Tierce de Picardie (Picardy third). In a Tierce de Picardie, a predominantly - or, more often, wholly - minor melody ends with the major instead of a minor third.
Examples: Elgar, theme from the 'Enigma Variations'. 'Coventry Carol'
Taken from: Unit 16, p.63
Definition: A time signature looks like a fraction and is placed at the beginning of a piece of music. It indicates the metre of the piece.
Examples:
=
four crotchets per bar
See also: Metre - compound and Metre - simple
Taken from: Unit 1, p.14
Definition: Tonic Sol-fa indicates the individual degrees of the scale and was pioneered by John Curwen (1816 - 1880). It was made famous in 'The Sound of Music'.
Doh - Ray - Me - Fah - Soh - Lah - Te - Doh
See also: Tonic Sol-fa chart
Taken from: Unit 6, p.68
Definition: Transcription means one of the following:
1) a change of notational system (such as doubling or halving all note values for ease of reading)
2) the notating of an unnotated piece
3) the adapting of a piece for a medium other than the original
Taken from: Unit 15, p.30
Definition: Transposition takes place when music is written out at a different pitch from that which it was originally conceived. Each note is raised or lowered by the same interval.
Taken from: Unit 3, p.72
Definition: On stringed instruments, a tremolando (also tremolo) refers to very rapid repetitions of the same note(s) produced by quickly alternating bow directions. An unmeasured tremolo, indicated by three or more beams across the stem of the note(s), is one where the notes don't have precisely defined durations... where there are repetitions of pairs of notes; this is known as slurred tremolo. It is also a measured tremolo (that is, the notes are played as precise semiquavers). Similarly, there can also be a measured tremolo (on one note) and an unmeasured slurred tremolo (on a pair of notes). The slurred tremolo is also found in piano music.
Taken from: Unit 14, p.24
Definition: This category of ornaments involves the rapid alternation of the main note with the note above. The trill or shake may be shown in two ways (and you may sometimes find the two combined into one sign). Considerable variety is possible in the interpretation of trills, and the subject forms somethign of an intellectual battleground.
The trill also often conventionally ends with a dip below the main note.
Particularly in late 19th Century music, it is sometimes stylistically correct to start the trill, not on the main not, but on the upper note.
Taken from: Unit 17, p.27
Definition: A triplet is a group of three notes to be performed in the time of two of the same kind. It is a temporary change from two quaver groups to three...
is the same
value as 
Taken from: Unit 2, p.28
Definition: This is basically a four-note ornament. The shape of the ornament sign this time gives you a clear diagram of the notes that you play. These are upper note - main note - lower note - main note. As with the trill and the mordent, interpretations beginning on the 'upper note' and the 'main note' are also possible, and there are variations also according to rhythmic context.
Taken from: Unit 17, p.28
Definition: Like the mordent, the turn also comes in an 'inverted form', this time affecting the relative succession of upper-note and lower-note components.
