• Music workflows - Audacity now features several music related features, such as switching between hh:mm:ss time and Beats & Measures, and time-stretching clips to align them to a song's tempo.
• Time stretching - Hold Alt (macOS: Option) while hovering over the top third of a clip edge to stretch it.
• New exporter - Audacity now features a new export window with easier access to options such as sample rate and custom mapping (for 5.1 or 7.1 audio). Additionally, the "Browse" button uses the native file browser now!

Other changes

• For MP3, Audacity now always uses Joint Stereo mode, which always delivers the best possible quality.
• #4720 Simplified pasting logic.
• Simplified stereo tracks. Left and right channels now always have synchronized clip starts and ends, and the same sample rate in both channels.
• #5014 Added cursors trimming and stretching left and right, and changed the I-beam cursor to be less similar to either.
• #4448 When importing audio, the project sample rate no longer changes.
• #5204 The spectrogram colors are now perceptually uniform, and the colormap has gotten a name: Roseus. It also can be used for dataviz outside of Audacity, see here for more info! (Thanks, Myungchul Keum)
• New defaults: The Time Signature toolbar now gets shown, the solo button is set to multi-track mode, time tracks have a wider starting range.
• #5291 Unsquished the Audacity logo found in some places of the app.
• #2330 Clicking on the border of two clips no longer merges them.
• #2530 Overdubbing on Windows fails with WASAPI with default Recording device.
• #443 Built-in Opus support.

Libraries

• lib-time-and-pitch implements a time stretching algorithm originating in Staffpad.
• Audacity now uses Conan 2.
• Continued extracting code into libraries and modules, especially in the context of importing and exporting.

Bug fixes

• #3778 --nogap metadata no longer is ignored.
• #4410 fixed a crash with LV2 plugins (thanks jfroyall!).
• #2471 #4798 fixed some crashes related to macros.
• #4769 fixed a crash when pasting in certain configurations.
• #4677 Accessibility: GUI can be disabled again for VST2 plugins (thanks, David Bailes!).
• #4988 Accessibility: Restored window control IDs, improving NVDA compatibility (thanks again, David Bailes!).
• #4872 fixed a crash on launch on OSX 10.9 (thanks, René Bertin!).