P leased to D an automatic phonograph for two years. P agreed to supply the records and replace worn out parts. D agreed to share the proceeds with P but also to pay a minimum of $20 per week. P claims that D repudiated the contract and P never installed the machine. P sued and got a judgment for $836; the sum of $20 per week for 2 years less costs to P saved from nonperformance. D appealed.