Diffusion based Text-To-Music (TTM) models generate music corresponding to text descriptions. Typically UNet based diffusion models condition on text embeddings generated from a pre-trained large language model or from a cross-modality audio-language representation model. This work proposes a diffusion based TTM, in which the UNet is conditioned on both (i) a uni-modal language model (e.g., T5) via cross-attention and (ii) a cross-modal audio-language representation model (e.g., CLAP) via Feature-wise Linear Modulation (FiLM). The diffusion model is trained to exploit both a local text representation from the T5 and a global representation from the CLAP. Furthermore, we propose modifications that extract both global and local representations from the T5 through pooling mechanisms that we call mean pooling and self-attention pooling. This approach mitigates the need for an additional encoder (e.g., CLAP) to extract a global representation, thereby reducing the number of model parameters. Our results show that incorporating the CLAP global embeddings to the T5 local embeddings enhances text adherence (KL=1.47) compared to a baseline model solely relying on the T5 local embeddings (KL=1.54). Alternatively, extracting global text embeddings directly from the T5 local embeddings through the proposed mean pooling approach yields superior generation quality (FAD=1.89) while exhibiting marginally inferior text adherence (KL=1.51) against the model conditioned on both CLAP and T5 text embeddings (FAD=1.94 and KL=1.47). Our proposed solution is not only efficient but also compact in terms of the number of parameters required.

翻译：基于扩散的文本到音乐（TTM）模型能够根据文本描述生成相应的音乐。典型的基于UNet的扩散模型通常以预训练大语言模型生成的文本嵌入或跨模态音频-语言表征模型生成的嵌入作为条件。本研究提出了一种基于扩散的TTM模型，其UNet同时接受两种条件输入：（i）通过交叉注意力机制引入单模态语言模型（如T5）的文本表征；（ii）通过特征线性调制（FiLM）引入跨模态音频-语言表征模型（如CLAP）的全局表征。该扩散模型经过训练，能够同时利用T5提取的局部文本表征和CLAP提取的全局表征。此外，我们提出改进方法，通过均值池化和自注意力池化机制从T5中同时提取全局与局部表征。该方法无需依赖额外编码器（如CLAP）提取全局表征，从而减少了模型参数量。实验结果表明：相较于仅使用T5局部嵌入的基线模型（KL=1.54），结合CLAP全局嵌入与T5局部嵌入能显著提升文本遵循度（KL=1.47）。另一方面，通过提出的均值池化方法直接从T5局部嵌入提取全局文本表征，在生成质量上表现更优（FAD=1.89），虽然其文本遵循度（KL=1.51）略逊于同时使用CLAP与T5文本嵌入的模型（FAD=1.94，KL=1.47）。我们提出的解决方案不仅在参数量上高效，而且具有结构紧凑的优势。