& A most popular Czech luluby (did you hear ir already?)
500
 & The above number as a sole word on a line
 &  is the basic length of a sound / 1 ms (program's Play default is 400)
2 e 
 & 2 before tone code demands e'', 
 & and initializes that octave until further occurence (default is ' octave); 
d 2
 & The number following a tone code gives multiple of the basic sound length,
 &  1 is its initial value, no value means the preceding one holds.
e 1
c 2
e 1
d 2
e 1
c 2

n 3
 & (any other word than tone code means a pause, 
 &  this time before the next strophe)

800
1 e 1    now one octave lower
d 2
e 1
c 2
e 1
d 2
e 1
c 2