Fractional Fourier Transform (FRFT) is a generalization of FT. In a high-level term is rotates the time-frequency plane about continuous angles. FT is just a special case of rotation about 90 deg (IFT rotates 90 deg back).
Even FRFT can be generalized further to Linear Canonical Transform (LCT). It provides a general linear transformation of the time-frequency plane.
Could FrFT or LCT be utilized somehow in audio processing?