Analyze audio files or microphone input with a real-time spectrum and spectrogram. Check clipping, noise, hum, loudness, and True Peak.

Reads audio from Windows audio interface or wave file and creates a continuous spectrum display. Command line support for generating sine, square, triangle and sawtooth wave files. Uses biquad IIR digital filters for frequency detection, plus digital lowpass filters for smoothing. Highly configurable. 60+ FPS with suitable hardware. Manual or automatic gain control.
Features:
- Continuous display update
- Single function, easy to learn
- Zoom in on small frequency or dB range
- Resizable main window and repartitionable panes
- Crosshair cursor when Ctrl is pressed
- Single, stand-alone exe file, no install/uninstall
- Builds with Visual Studio 2019 or 2022
- Bit-perfect sine wave generation for all sample sizes

TiMidity++ is a software synthesizer. It can play MIDI files by converting them into PCM waveform data; give it a MIDI data along with digital instrument data files, then it synthesizes them in real-time, and plays. It can not only play sounds, but also can save the generated waveforms into hard disks as various audio file formats.
TiMidity++ is a free software, distributed under the terms of GNU general public license.
Features:
timidity.sourceforge.net
- Plays MIDI files without any external MIDI instruments at all
- Understands SMF, MOD, RCP/R36/G18/G36, MFI
- Converts MIDI files into various audio file formats: .wav, .au, .aiff, .ogg and so on
- Uses Gravis Ultrasound compatible patch files and/or SoundFonts as the voice data
- Displays information about the music that is now playing
- Various user interfaces: ncurses, gtk, Win32-GUI, and others
- Plays remote MIDI files over the network
- Plays MIDI files in archive files
- Displays sound spectrogram for the playing music
- Trace playing
sourceforge.net/projects/timidity