There is not all that much about Noël Coward’s brilliant 1941 play Blithe Spirit that would initially make you think “this needs to be a musical.” It’s a drawing room comedy, with a relatively small cast, and tightly-written That doesn’t leave itself room for opening up or expanding in the way that musicals traditionally are. On the other hand, Blithe Spirit features an array of colorful, larger-than-life characters, including a wacky medium and an insane diva who happens to be a ghost. Suddenly, the prospects for musical comedy seem just a bit more accessible. That must be what Timothy Gray and Hugh Martin had in the front of their minds when they conjured up the musical High Spirits, adapted for the musical stage from Coward’s Blithe Spirit.