What are Open Source Music Generation Models?
Open source music generation models are specialized AI systems that create audio content from text descriptions or other inputs. Using advanced deep learning architectures like dual autoregressive transformers and large language models, they translate natural language prompts into high-quality speech and audio. This technology allows developers and creators to generate, modify, and build upon audio content with unprecedented freedom. They foster collaboration, accelerate innovation, and democratize access to powerful audio creation tools, enabling a wide range of applications from music production to enterprise voice solutions.
Fish Speech V1.5
Fish Speech V1.5 is a leading open-source text-to-speech (TTS) model employing an innovative DualAR architecture with dual autoregressive transformer design. It supports multiple languages with over 300,000 hours of training data for English and Chinese, and over 100,000 hours for Japanese. In TTS Arena evaluations, it achieved an exceptional ELO score of 1339, with a word error rate of 3.5% and character error rate of 1.2% for English, and 1.3% CER for Chinese characters.
Fish Speech V1.5: Multilingual Excellence in Speech Synthesis
Fish Speech V1.5 is a leading open-source text-to-speech (TTS) model employing an innovative DualAR architecture with dual autoregressive transformer design. It supports multiple languages with over 300,000 hours of training data for English and Chinese, and over 100,000 hours for Japanese. In independent evaluations by TTS Arena, the model performed exceptionally well, with an ELO score of 1339. The model achieved a word error rate (WER) of 3.5% and a character error rate (CER) of 1.2% for English, and a CER of 1.3% for Chinese characters.
Pros
- Exceptional ELO score of 1339 in TTS Arena evaluations.
- Innovative DualAR architecture for superior performance.
- Extensive multilingual support with massive training datasets.
Cons
- Higher pricing compared to other TTS models.
- May require technical expertise for optimal implementation.
Why We Love It
- It delivers industry-leading performance with multilingual capabilities, making it the gold standard for high-quality speech synthesis applications.
CosyVoice2-0.5B
CosyVoice 2 is a streaming speech synthesis model based on a large language model with unified streaming/non-streaming framework design. It achieves ultra-low latency of 150ms while maintaining high synthesis quality. Compared to version 1.0, pronunciation error rates are reduced by 30%-50%, MOS score improved from 5.4 to 5.53, with fine-grained control over emotions and dialects including Chinese dialects, English, Japanese, and Korean.
CosyVoice2-0.5B: Real-Time Streaming with Emotional Control
CosyVoice 2 is a streaming speech synthesis model based on a large language model, employing a unified streaming/non-streaming framework design. The model enhances the utilization of the speech token codebook through finite scalar quantization (FSQ), simplifies the text-to-speech language model architecture, and develops a chunk-aware causal streaming matching model that supports different synthesis scenarios. In streaming mode, the model achieves ultra-low latency of 150ms while maintaining synthesis quality almost identical to that of non-streaming mode. Compared to version 1.0, the pronunciation error rate has been reduced by 30%-50%, the MOS score has improved from 5.4 to 5.53, and fine-grained control over emotions and dialects is supported.
Pros
- Ultra-low latency of 150ms in streaming mode.
- 30-50% reduction in pronunciation error rates.
- Improved MOS score from 5.4 to 5.53.
Cons
- Smaller parameter size compared to larger models.
- Limited to streaming and speech synthesis applications.
Why We Love It
- It combines real-time performance with emotional intelligence, making it perfect for interactive applications requiring natural, expressive speech synthesis.
IndexTTS-2
IndexTTS2 is a breakthrough auto-regressive zero-shot Text-to-Speech model addressing precise duration control challenges in large-scale TTS systems. It features disentanglement between emotional expression and speaker identity, enabling independent control over timbre and emotion. The model incorporates GPT latent representations and a novel three-stage training paradigm, with soft instruction mechanism based on text descriptions for emotional control.
IndexTTS-2: Advanced Duration and Emotion Control
IndexTTS2 is a breakthrough auto-regressive zero-shot Text-to-Speech (TTS) model designed to address the challenge of precise duration control in large-scale TTS systems, which is a significant limitation in applications like video dubbing. It introduces a novel, general method for speech duration control, supporting two modes: one that explicitly specifies the number of generated tokens for precise duration, and another that generates speech freely in an auto-regressive manner. Furthermore, IndexTTS2 achieves disentanglement between emotional expression and speaker identity, enabling independent control over timbre and emotion via separate prompts.
Pros
- Breakthrough zero-shot TTS capabilities.
- Precise duration control for video dubbing applications.
- Independent control over timbre and emotion.
Cons
- More complex setup compared to standard TTS models.
- Requires both input and output pricing structure.
Why We Love It
- It revolutionizes TTS with precise duration control and emotional disentanglement, perfect for professional video dubbing and advanced speech synthesis applications.
AI Model Comparison
In this table, we compare 2025's leading open source music generation models, each with a unique strength. For multilingual excellence, Fish Speech V1.5 provides industry-leading performance. For real-time streaming applications, CosyVoice2-0.5B offers unmatched low latency and emotional control, while IndexTTS-2 prioritizes advanced duration control and zero-shot capabilities. This side-by-side view helps you choose the right tool for your specific audio generation or synthesis goal.
| Number | Model | Developer | Subtype | Pricing (SiliconFlow) | Core Strength |
|---|---|---|---|---|---|
| 1 | Fish Speech V1.5 | fishaudio | Text-to-Speech | $15/M UTF-8 bytes | Multilingual excellence & high ELO score |
| 2 | CosyVoice2-0.5B | FunAudioLLM | Text-to-Speech | $7.15/M UTF-8 bytes | Ultra-low latency streaming |
| 3 | IndexTTS-2 | IndexTeam | Text-to-Speech | $7.15/M UTF-8 bytes | Precise duration & emotion control |
Frequently Asked Questions
Our top three picks for 2025 are Fish Speech V1.5, CosyVoice2-0.5B, and IndexTTS-2. Each of these models stood out for their innovation, performance, and unique approach to solving challenges in text-to-speech synthesis, multilingual support, and advanced audio generation capabilities.
Our in-depth analysis shows several leaders for different needs. Fish Speech V1.5 is the top choice for multilingual applications requiring the highest quality output. For real-time streaming applications, CosyVoice2-0.5B excels with 150ms latency. For advanced control over duration and emotions, IndexTTS-2 is ideal for professional video dubbing and complex speech synthesis.