Task 2 is in two parts: For Task 2A, the pitches are pre-composed;
作业2分做两部份：在作业2A，音高是事先作好的；
This article described a general method for creating composed patterns from pre-existing patterns and explained how to design and implement one, using a detailed example.
本文描述了从已存在的模式中创建复合模式的普遍方法，并通过一个详细的例子解释了如何设计与实现。
The endpoint reference is dynamically composed at runtime, without requiring a pre-existing SCA import.
端点引用将在运行时进行动态组合，从而不需要预先存在的 SCA 导入。
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