I decided to give it a try, because at the Renaissance festival I worked at, they played lots of music that wasn't playable on a whistle, due to the key signatures or sharps/flats within the tunes. Clarinet is 3.5 octaves, fully chromatic (all the sharps and flats). But that means in addition to the 6 holes, there are cross fingerings (like on the recorder) where aren't just going up and down the holes, a back hole, and 9 additional keys to learn, so it's taking some time.