SoulX-Singer

SoulX-Singer is a singing-voice synthesis and vocal-conversion model for people who want to shape performances rather than accept a fixed vocal result. It is best suited to researchers and developers comfortable with a local workflow; its combination of score control and MIDI editing is compelling, provided you are prepared to check automatic transcription and alignment.

Overview

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

SoulX-Singer supports Mandarin Chinese, English, and Cantonese, including cross-lingual synthesis and lyric editing intended to preserve natural prosody. The project reports training on more than 42,000 hours of aligned vocal, lyric, and note data. Its Apache 2.0 code and model weights may be used commercially, but the maker prohibits unauthorized impersonation and deceptive audio and asks users to respect privacy, consent, and intellectual property.

Key features

Shape pitch, rhythm, and expression

Performance control comes through either melody-conditioned F0 contours or score-conditioned MIDI notes. The latter is useful when you want to work from a score and refine musical details rather than steer pitch alone. A MIDI Editor supports changes to lyrics, phoneme alignment, pitches, and durations; edited metadata can be imported back for synthesis.

Convert vocals and prepare material

SoulX-Singer-SVC converts singing audio into a target singer’s voice while retaining the source performance’s melody, rhythm, and lyrics. The preprocessing toolkit can separate vocals, remove reverberation, extract F0, detect voice activity, and transcribe lyrics and notes. This breadth supports an end-to-end workflow, but automatic preprocessing can misalign audio with lyrics and notes. The maintainers recommend manual correction, so users should treat its output as a starting point, not a final score.

Pricing

SoulX-Singer costs nothing. Researchers and developers can use the code and weights under Apache 2.0, and commercial use is allowed. There is no paid tier or usage quota described in the plan; the trade-off is that deployment is a technical workflow rather than a priced hosted service. Consent and impersonation restrictions still apply.

Platforms

The project supports Linux and self-hosted deployment, and offers web access through running singing-generation, vocal-conversion, and MIDI Editor demos on Hugging Face Spaces. For local inference, the repository uses Conda, Python 3.10, pip-installed dependencies, and web UI scripts. Pretrained synthesis, conversion, and preprocessing models are downloaded through Hugging Face Hub commands. The web demos offer a route to try the tools without setting up local inference; the local route is better suited to users who want to build a repeatable workflow.

Who it's for

Choose SoulX-Singer if you are a researcher or developer who needs zero-shot singing synthesis, voice conversion, and detailed MIDI-based editing in one project, especially across its three supported languages.

Pros and cons

• Pros: Zero-shot synthesis avoids per-singer fine-tuning, while conversion preserves the source song’s melody, rhythm, and lyrics.
• Pros: F0 and score-based controls, plus MIDI editing of lyrics, phonemes, pitches, and durations, provide meaningful performance-level revision.
• Pros: Apache 2.0 licensing permits commercial use of the code and weights.
• Cons: Automatic preprocessing may misalign lyrics and notes, making manual correction part of a reliable workflow.
• Cons: Local deployment requires Conda, Python 3.10, dependency installation, and model downloads, which is a hurdle for users seeking a ready-to-use desktop app.

Alternatives

Revocalize AI is worth considering if you want a freemium option across web, mobile, desktop, and other platforms; 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 using generated audio inside an application requires separate permission.

Kits AI suits readers seeking a web or API service with a free monthly allowance of 15 conversion minutes, voice designer/blender, and generative vocals; its Free plan has zero voice slots and download minutes.

VoiSona Song is an alternative for users looking for a singing software option on iOS, macOS, or Windows.

Audimee offers a web-based alternative with 15 free conversion minutes, 11 royalty-free voices, and MP3 downloads for personal use; its Free plan has no custom voice model slots.

LyricToMelody AI is a web option for lyric-first draft generation, with 20 starting credits and MP3, WAV, and PCM export on its free Starter plan.

SightSinger is another web-based option.

Sinsy is a free online alternative that generates singing vocals from an uploaded MusicXML score.

Browse more options in AI Singing Voice Generators and AI Song Cover Generators.

Verdict

SoulX-Singer is a strong fit for researchers and developers who need controllable, zero-shot singing synthesis and vocal conversion, with MIDI editing and commercial use under Apache 2.0. Its main reason to choose it is the depth of musical control across synthesis and conversion; look elsewhere if you need a consumer-ready workflow that does not depend on technical setup or manual alignment checks.