Jane's Conference / Bitterspring has released 4 Band Shifter, a free open source VST effect plug-in for Windows that is able to shift independently the pitch of 4 adjacent, user-definable frequency bands. Code is based on Stephan M. Bernsee's article, Pitch Shifting Using Fourier Transform.

Features:

• Fast: it uses FFTW library to perform fast STFTs.
• Can shift each frequency band independently in a range of (-12, +12) semitones.
• Big display representing the frequency bands / gain per band / volume per band.
• Can work in continuous or discrete mode.