principles: Add section about wider transformation

PRINCIPLES.md

@@ -38,3 +38,22 @@ It provides a framework for sharing that media between systems, solutions and or
    We make decisions with strong engineering justification and consider the impact of change, through an open decision process.
 9. The TAMS community is governed by a balanced mix of users (broadcasters, content owners etc.) and technology/solution vendors.
 10. When common requirements arise, or the need for a common piece of functionality becomes clear, we attempt to standardise an approach either in the API Specification or an Application Note to enable interoperability.
+
+## The Bigger Picture
+
+TAMS is part of a bigger transformation of how media workflows, supply chains and the organisations that run them work in an increasingly software-defined world.
+In the past, a conventional view of broadcast technology was to build a physical facility and deploy a technical estate that suited the organisation for a timeline measured in years.
+This has already changed, with many organisations looking to the cloud for more flexibility, and accepting capable but monolithic solutions either managed in their own cloud infrastructure, or through a SaaS model.
+
+However the needs of audiences and the shape of media and entertainment markets continue to shift, and shift very rapidly, demanding agility from the broadcasters, distributors and content creators that serve them.
+To support that agility, media organisations want to take smaller components from the market that integrate well together on shared interoperable foundations.
+They want to join components together around functional blocks and be free to experiment with new experiences and capabilities, deciding in each case whether to buy from the market, build themselves or assemble from smaller pieces.
+
+TAMS solves one particularly troubling problem in this tranformation: sharing media between tools and systems, whether they are in the cloud, in a facility or in the field.
+End-users can assemble powerful workflows out of those tools and systems, with confidence in interoperability through TAMS, and the agility to replace/upgrade or innovate as they see fit.
+
+The need for open standards is well understood by the broadcast sector: many industry organisations have a long history of developing and managing standardisations efforts.
+The challenge is the speed of change: TAMS has deliberately taken a "rough consensus and running code" approach ([borrowed from the IETF](https://www.ietf.org/runningcode/)), working as an iterative open source project that evolves fairly quickly but has strong versioning semantics to assure interoperability.
+TAMS is not the only project on this journey, for example the [Media eXchange Layer (MXL)](https://github.com/dmf-mxl/mxl) takes the same open-source approach for low-latency live production under the [Dynamic Media Facility](https://www.amwa.tv/jtdmf) initiative.
+
+As our market continues to shift and blur the traditional lines between broadcasters, content creators and distribution platforms, an open source approach and common foundations enables the technology to serve the needs of creative teams, rather than the other way around.