to add harmonies to a tune

to be suitable together, or to make different people, plans, situations, etc. suitable for each other

The garden has been designed to harmonize with the natural landscape. 这个花园设计得与自然景观很协调。

The plan is to harmonize (= make similar) safety standards across all the countries involved. 这个计划旨在使所有相关国家的安全标准保持一致。