### Clue: A serving figure in a party progressing slowly in bars (6)
### Answer: ADAGIO 
 ### Explanation: Definition: progressing slowly in bars
 [A + GI(abbrev. for a person serving in the US Army) ] **contained in**(in) [ A + DO(a party;a social function) ].
Defn: …, bars that a music score is divided into, that is.