Though the use of the Fast Fourier Transform (FFT) for signal processing in music applications has been widespread, applications in real-time systems for dynamic spectral transformation has been quite limited. The limitations have been largely due to amount of computation required for the operations. With faster machines, and with suitable implementations for frequency-domain processing, real-time dynamic control of high-quality spectral processing can be accomplished with great efficiency and simple approach. This paper will focus on dynamic real-time control of frequencydomain-based signal processing, and will describe the author's latest work (hi-resolution filtering and spatialization implementations) in this area. General background on the implementation and the development environment (Max Signal Processing, MSP) will also be provided.