In this seminar, we discuss two recent applications of the theory of isomonodromic deformations. The first is a new method to calculate black hole quasinormal modes. These modes can be detected in the gravitational wave signals from black hole mergers. We apply this method to the 4-dimensional rotating black hole in an accelerated expanding universe 
(Kerr-de Sitter black hole).  The second application is the calculation of classical conformal blocks in 2D conformal field theory. These can be useful to calculate entanglement entropy of excited states in the large central charge limit.