set with the @code{\tempo} command:
@lilypond[verbatim,quote]
-\relative c'' {
+\relative {
\time 3/4
\tempo "Andante"
- a4 a a
+ a'4 a a
\time 6/8
\tempo 4. = 96
a4. a
Here is a small example showing all these elements together:
@lilypond[verbatim,quote]
-\relative c, {
+\relative {
\clef "bass"
\time 3/4
\tempo "Andante" 4 = 120
- c2 e8 c'
+ c,2 e8 c'
g'2.
f4 e d
c4 c, r