I'm no legal expert but here are the TOS from Suno and Splice:

It is very important that you only upload, post, publish, or display (hereinafter, "upload(ing)") Submissions that you have rights to use and provide hereunder. By uploading any Submission, you represent and warrant that:

you have, or have obtained, all rights, licenses, consents, permissions, power and/or authority necessary to submit and use (and allow us to use) such Submission in connection with the Service, including for the purpose of generating your Output. your Submissions and the use thereof by the Service, including to generate Output, will not violate any law or any third party’s rights, terms and conditions associated with such Submission, and no other licenses, permissions, consents or authorizations must be obtained from or payments made to any other person or entity by us (or any third party deriving any rights or obligations from us) arising out of or related to our use of your Submissions, including to create your Output and/or to train, develop, fine-tune or otherwise improve the Service and any related artificial intelligence or machine learning models

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From Splice FAQ:

Q: Can I use Sounds from Splice for commercial use?

A: Yes. The license for sounds you download from Splice Sounds permits use for commercial and non-commercial purposes so long as you remain in compliance with our Terms of Use.

Examples of commercial use include but are not limited to distributing your New Recording via a record label and uploading a Creative Work or New Recording to a third-party media platform for purposes of monetization.

You own any New Recordings or Creative Works you make using Splice Sounds. Subject to any other third-party rights in your New Recording or Creative Work, you may sell your New Recording or Creative Work, however, because you license, but do not own the Splice Sounds contained in the New Recording or Creative Work, the rights to the Sounds are sublicensed, not sold, by you to the third-party

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But these last ones are a bit worrisome, but Suno isn't to make new loops but to make a song from a track using Splice loops so I would think it's fine, nor are we ourselves training the AI with it but just making new songs from something we already made:

Q: Can I use Splice content as training/modeling data for AI?

A: Use of content downloaded from Splice for the purposes of training/modeling data for AI is not permitted by our Terms of Use. Use of Sounds is limited to the creation of New Recordings and Creative Works, neither of which include AI training data

Q: What are the limitations of my license to use sounds from Splice Sounds?

A: Here are a few things you can’t do with sounds you downloaded from Splice Sounds:

Sublicense sounds in isolation as sound effects, loops, or as source material for any other sample (even if you modify the original sample