Audjust AI Music Remixer vs StemForge

Audjust AI Music Remixer takes an uploaded song and creative settings and turns them into a production brief for a newly arranged version. Users can choose a genre, target BPM, vocal direction and language, how strongly to change the style, and how much melody to preserve. The target tempo can be set from 60 to 200 BPM, though the result is not guaranteed to match it exactly. Vocal settings are guidance; the tool does not promise a particular voice or clone a named real singer. Uploads can be up to eight minutes and 50 MB in MP3, WAV, M4A, AAC, OGG, or FLAC format. Each generation costs 30 credits. Jobs run asynchronously through supported providers, with fallback processing for qualifying technical failures; failed jobs do not consume credits, but content-policy and catalog-match errors are not bypassed. Successful results are saved in My Audios for download and follow-up work. The web service has Free, Lite, Pro, and Premium plans, and credit packs can be added to any plan. Paid plans include commercial use for generated music, but users remain responsible for rights to source audio they upload.

StemForge is a locally run, browser-based audio workstation for separating stems, extracting MIDI, generating audio, composing songs, mixing, and exporting. Demucs and BS-Roformer can separate audio into vocal, drum, bass, other, guitar, and piano stems; spectral analysis informs engine and model recommendations. For MIDI extraction, StemForge uses BasicPitch on instrument stems and faster-whisper with pitch tracking on vocal melodies. Its Synth tab generates text-conditioned audio with Stable Audio Open for up to 600 seconds, with optional audio or MIDI conditioning. Compose uses AceStep for song generation and RVC for voice conversion, with 14 built-in voices and a HuggingFace model browser. Mix combines stems, MIDI-rendered tracks, synth outputs, and composed songs; exports include WAV, FLAC, MP3, and OGG, individually or in a ZIP. The project says audio remains on the user's computer and no internet is needed after initial model downloads. Setup requires Python 3.12, FFmpeg, and FluidSynth with a GM soundfont. The software is free and open source.