Overview

The model can synthesize a voice for a singer it has not encountered, without speaker-specific fine-tuning. It can also convert raw singing audio to a target singer’s voice while retaining melody, rhythm, and lyrics, without requiring lyric or MIDI transcriptions. That makes it relevant both to vocal creation and to changing the timbre of an existing performance.

SoulX-Singer supports Mandarin Chinese, English, and Cantonese. The project reports training on more than 42,000 hours of aligned vocals, lyrics, and notes, and includes cross-lingual synthesis and lyric editing intended to preserve natural prosody. Its code and weights use Apache 2.0, commercial use is allowed, and the maker prohibits unauthorized impersonation and deceptive audio while asking users to respect privacy, consent, and intellectual property.

Key features

Performance control and MIDI editing

Pitch can be guided with melody-conditioned F0 contours or score-conditioned MIDI notes; the latter provides control over pitch, rhythm, and expression. A MIDI Editor supports changes to lyrics, phoneme alignment, pitches, and note durations before inference, with generated metadata exportable to MIDI and editable material importable back into synthesis. This is a substantial advantage for users who want to revise musical structure rather than accept a fixed vocal result, though it also makes the tool better suited to a production workflow than a one-click song generator.

Conversion and preparation

SoulX-Singer-SVC converts raw singing into a target singer’s voice without lyric or MIDI transcription, preserving the source performance’s melody, rhythm, and words. The preprocessing toolkit handles vocal separation, dereverberation, F0 extraction, voice activity detection, lyric transcription, and note transcription. Those steps broaden the material users can bring into the workflow, but automatic preprocessing can misalign audio with lyrics or notes. The maintainers recommend manual correction, so users should budget time to review alignment instead of assuming every input is ready for synthesis.

Web demo and local inference

Soul-AILab provides singing-generation and vocal-conversion demos on Hugging Face Spaces, plus a separate MIDI Editor Space. For local inference, the repository supports Conda with Python 3.10, pip-installed dependencies, and WebUI scripts; pretrained synthesis, conversion, and preprocessing models are downloaded through Hugging Face Hub commands. The demo offers a lower-setup way to explore the workflow, while local deployment gives researchers and developers a route to run it themselves. The local path requires comfort with environment setup and model downloads.

Pricing

SoulX-Singer is free: the SoulX-Singer plan costs 0.00 USD per free. Researchers and developers may use the code and model weights under Apache 2.0, and commercial use is allowed. There is no paid tier or seat or usage quota described for this plan; the relevant trade-off is operational rather than financial, since local use involves setup and preprocessing review.

Platforms

SoulX-Singer supports Linux and self-hosted deployment, with web access through the maker’s Hugging Face Spaces demos. It is not presented as a conventional mobile or desktop consumer app; the local workflow is built around Conda, Python, dependencies, and WebUI scripts.

Who it's for

This is a strong fit for researchers and developers exploring singing synthesis, voice conversion, or vocal tooling who value pitch and score control, MIDI editing, and local inference. It can also suit creators who need conversion or cross-lingual synthesis, provided they are prepared to inspect preprocessing alignment and use voices responsibly. Readers looking for a polished, low-effort consumer app or a workflow that never needs manual correction should look elsewhere.

Pros and cons

Pros

Zero-shot synthesis and voice conversion cover both creating a singer’s voice and changing an existing vocal performance without per-speaker fine-tuning.
F0 and MIDI control, plus editable lyric, phoneme, pitch, and duration data, give technically minded users meaningful ways to shape a performance.
Apache 2.0 licensing permits commercial use, and the project provides web demos as well as a local inference path.

Cons

Automatic preprocessing may misalign lyrics and notes with singing audio, making manual correction part of a dependable workflow.
Local inference requires a Conda and Python setup, dependency installation, and model downloads, which adds friction for casual users.
The three supported languages are Mandarin Chinese, English, and Cantonese, so users working in other languages should not assume coverage.

Alternatives

For a broader directory of tools in this category, browse AI Singing Voice Generators or AI Song Cover Generators.

Revocalize AI is worth considering for a wider set of platforms, including mobile and desktop; its free plan includes 5 conversion minutes per month and one Starter AI voice.
NEUTRINO is another free option for general music and audio production, though system integration or embedding generated audio in an application requires separate permission.
VoiSona Song is an alternative for users seeking a singing tool on iOS, macOS, or Windows.
Kits AI is a web and API alternative whose free plan includes 15 conversion minutes and Kits generative vocals.
Audimee may suit web users seeking royalty-free voices; its free plan offers 15 minutes of conversions and MP3 downloads for personal use.
LyricToMelody AI is a web alternative for lyric-first draft generation, with 20 starting credits, MP3, WAV, and PCM export, and seven-day project retention on its free Starter plan.
SightSinger is another web-based option.
Vocalize offers API and web access with per-minute and per-request charges rather than a subscription.

Verdict

Choose SoulX-Singer if you are a researcher or developer who wants open-source singing synthesis and conversion with fine-grained performance and MIDI control. Its zero-shot workflow, local deployment, and commercial-use license make it unusually adaptable for that audience. Look elsewhere if you need a hands-off consumer experience: preprocessing alignment can require correction, and local inference takes technical setup.

	SoulX-Singer	VOCALOID6
Free plan	Yes	No
Free trial	No	Yes
Paid from	Free	—
Open source	No	No
Platforms	Linux, self-hosted, Web	macOS, Windows
Export formats	MIDI	—
Commercial use	allowed	allowed
Free plan	—	No

SoulX-Singer vs VOCALOID6

SoulX-Singer

VOCALOID6