Because good musicians playing in a big band are like samurai deigning to fight without hope of glory, of course. They have to really love what they do, and they have to be willing to be paid in rice if need be.
Kambei Shimada, pondering the prospect:
First of all, it's not easy to find trustworthy samurai. What's more, all you have to offer is food. Only those out to fight for the hell of it will agree. Besides, I'm sick of fighting. Age, I suppose.
Kambei Shimada, attempting to convince another samurai to join the cause:
Kambei Shimada: It pains me to tell you, but we're fighting for farmers.
Potential comrade: Farmers?
Kambei Shimada: That's right. This job offers no stipend and no reward. But we can eat our fill as long as we fight.
Potential comrade: This is absurd! My ambitions are greater than that.
Kambei Shimada: That's a shame. Won't you reconsider?
Potential comrade: I will not.
Katsushirō Okamoto: Sir, we lost a good man there. Such a fine swordsman.
The few and the proud.