Possible Clues:

• Victor Hugo novel
• Hugo-based musical
• Well-known musical
• Musical based on a novel by Victor Hugo
• Did Hugo provide us with not so much about what's so sad
• Did Hugh go, by the sound of it, and make the mean seaman come between one Leslie and the other one?
• 1935 film, remade in 1952, also a West End musical
• Victor Hugo novel, Valjean its hero
• Scrooge practised interrupting to smaller extent - that's novel
• Skinflint's smart to get into smaller show