SINATRA and  "Glad to Be Unhappy."   Rodgers & Hart  were always able to combine a lovely melody with often tart and seditious lyrics.
The title may seem to be contradictory-how can  one be  glad while at the same time being unhappy ?

It appears that Lorenz Hart believed that the ardour and headlong  pursuit of a love object is so exhilarating that even an unsuccessful affair can make one  euphoric . The song ends with " I'm so unhappy-But Oh so glad. "
Frank Sinatra's many romantic interludes were marked by the same sad/glad dichotomy and this song does reflect many of his own sentiments.
https://youtu.be/Kx2jhrimuGs