Audacity
audacityteam.org
Audacity is an easy-to-use, multi-track audio editor and recorder for Windows, macOS, and Linux. It supports recording live audio, converting tapes and records into digital files, cutting and mixing tracks, and applying digital effects such as noise reduction, equalization, and pitch/tempo manipulation. It supports a wide array of formats including WAV, MP3, FLAC, and OGG.