Sonance, Mac Audio Spectrum Analyzer, Spectrograph, and Music App
Audio Spectrum Analyzer with EM800 tubes called "Magilyzer" by Juergen Grau — Kickstarter
Spectrum Audio Analyzer Pro for Mac - Download
nomp3
MP3 bitrate detection through frequency spectrum analysis - Stack Overflow
Sound Spectrum Analyzer - Apps on Google Play
This Handy Tool Checks The REAL Quality Of Your Music Files | News | Deep House Amsterdam
Multicolor Led Music Spectrum Display Analyzer Car Mp3 Amplifier Audio 20 Level Indicator Rhythm Vu Meter Clock Usb 5v 12v - Replacement Parts - AliExpress
Making an Audio Spectrum analyzer with Bass.dll, C# and Arduino - CodeProject