Sonic Visualiser

To study a recording's structure, pitch, and beats, a plain player only lets you listen. Sonic Visualiser opens music up: a tool for visualizing, analyzing, and annotating music recordings to inspect sound in detail.

Features

Audio Visualization: Waveform, spectrum views.

Analyze & Annotate: Mark structure and features.

Plugin Analysis: Add analysis plugins.

Open Source: Cross-platform, free.