What are the best sources of information on mechanical royalty rates and terms?

Established by the Copyright Royalty Board (CRB) in the US, these are minimum rates used as a baseline when no specific agreement exists.

This is correct, however masters also have Mechanicals (sometimes known as dubbing or reproduction rights) which are priced differently on a per territory basis. Statutory licenses are available for non-interactive uses in the US via sound exchange but interactive streaming worldwide is usually administered by labels directly. There are industry norms with regards to splits and minimums but each deal is unique.

Agreements between songwriter organizations and licensing entities can provide insights into standard royalty rates for specific regions or media formats.

While less standardized, negotiated deals between rights holders and licensees can offer valuable benchmarks, though confidentiality might limit accessibility.

Direct license terms for digital and sync/master use usually have boiler plate language around warranties, usage, liability and indemnities etc which is rarely negotiable. It is also a mistake to assume bespoke deals allow licensees to adjust terms to suit their needs. Regardless of your needs, you can expect direct deals to always conform to precedents (which you’ll struggle to find information about online) commonly on a service / exploitation type basis. It takes skilled negotiation and a highly justifiable argument to challenge this conformity, especially for digital; but be sensible and realistic with your asks and many rights holders are open to breaking ground. Put yourself in their shoes or you’ll walk away disappointed.

Royalty collection societies and music licensing platforms often have online resources with royalty rate information and calculators.

Organizations like the World Intellectual Property Organization (WIPO) provide information on international copyright laws and royalty collection societies.

Legal resources; copyright law firms or intellectual property specialists can provide tailored advice based on your specific situation. Industry Publications; trade publications or online music industry news sources might feature articles or discussions on royalty rates and trends. Professional organizations; organizations like the National Music Publishers' Association (NMPA) or the American Society of Composers, Authors and Publishers (ASCAP) advocate for songwriters' rights and might offer resources or guidance.