If
no indication is given, a sequence of symbols is interpreted as "one symbol per
time unit". We mean
**symbolic**
time units counted on a
**symbolic
tempo**.
Sound-object sequence "a b c d e f" may also be notated "/1 a b c d", where
"/1" is called an
**explicit
tempo marker**.
Similarly, if the same sequence is to be interpreted three times faster it is
notated "/3 a b c d e f".

Using
explicit tempo markers makes it possible to change tempo within the string.
For instance, in sequence

/2
a b c d e f /3 g h i j k l m n o

'a'
... 'f' are interpreted at speed 2 (two sound-objects per beat) while 'g' to
'o' are interpreted at speed 3. (This may also be viewed as a tempo
acceleration of 3/2.) If '_' (empty sound-object) is used to denote a
prolongation of the preceding object, the same expression may equivalently be
notated:

/6
a_ _ b_ _ c_ _ d_ _ e_ _ f_ _ g_ h_ i_ j_ k_ l_ m_ n_ o_

Gaps
(silences
or rests) are written as hyphens or integer numbers. The following notations
are equivalent:

/2
a b - - c d /3 e - - - - f g h

/2
a b 2 c d /3 e 4 f g h

/1
a b /2 c d e f 4/3 g h

in
which 'a' and 'b' are interpreted at speed one, 'c', 'd', 'e', 'f', "g" and
"h" at speed two while sequences "cdef" and "gh" are separated with a silence
of duration 4/3. Since the "4/3" silence occurs at speed two its actual
symbolic duration
is 4/3 x 1/2 = 2/3. Here again BP2 will expand the representation to

/6
a _ _ _ _ _ b _ _ _ _ _ c _ _ d _ _ e _ _ f _ _ - - - - g _ _ h _ _

where
the "4/3" gap is represented as "- - - -" (or "- _ _ _" equivalently). The
following representations are equivalent:

/6
a _ _ _ _ _ b _ _ _ _ _ c _ _ d _ _ e _ _ f _ _ - _ _ _ g _ _ h _ _

/6
a _ _ _ _ _ b _ _ _ _ _ c _ _ d _ _ e _ _ f _ _ 4 g _ _ h _ _