Bring Me the Head of Alfredo Garcia (1974)

In Mexico, the wealthy father of a pregnant young woman offers $1million for the head of the man who impregnated her. A pair of bounty hunters meet a local piano man in their search. The piano player does a little investigating and finds out that his girlfriend knows of Garcia's death and where his body is. Thinking he can make easy money, they set off on this goal, but the trip brings untold misery instead.