Try "The Pirates of Penzance" by Gilbert and Sullivan. It's not too long, there's talking as well as singing, it's in English and the story is quite simple. You may even recognise a few of the songs as there has been a Hollywood and Broadway version, I think Kevin Kline was in one. Basically, it about a bloke who was apprenticed by accident to a pirate instead of a ship's pilot until his 21st birthday. Having decided to leave the pirate group on that day, he tells them he will try to have them locked up. By a quirk of fate, he was born on 29th February so he will be about 84 when he is finally allowed to leave. There's a bit of romance, a few sub plots and a happy ending.