Can You Sing?

Shackleton was a great recruiter. Nearly 5,000 people applied for 30 spots on the ill-fated Endurance (although no historian has produced a verifiable copy of the renowned help wanted ad). Shackleton used all kinds of inventive techniques to probe for what made the applicants tick, such as asking hard-boiled sailors to sing (a test of whether they would boost or sap morale on a long voyage).

- from Mavericks at Work