This paper proposes a new morphing method to generate a melody, given two melodies represented by time-span trees obtained from the generative theory of tonal music (GTTM). In this paper, we define a feature structure based on a time-span tree and the distance between two structures. Next, we construct a lattice of subsumption relations among these structures and define three algebraic operations: reduction, meet, and join. First, we conduct these operations in the pure algebraic domain and a new melody is as an interpolation in the lattice; thereafter, we render the obtained tree into a music melody, assigning a priority order among candidate branches. We confirmed that our morphing algorithm generated new variations with satisfactory quality.

本文提出了一种新的变形方法来生成旋律，给定由音调音乐生成理论（GTTM）获得的时间跨度树表示的两个旋律。在本文中，我们定义了基于时间跨度树和两个结构之间的距离的特征结构。接下来，我们构建这些结构之间的包含关系格，并定义三个代数运算：归约、相遇和连接。首先，我们在纯代数域中进行这些运算，新的旋律作为格子中的插值；之后，我们将获得的树渲染成音乐旋律，并在候选分支之间分配优先级顺序。我们确认我们的变形算法生成了质量令人满意的新变体。