The phrase "minor phase" can be interchanged with a variety of synonyms, depending on the context in which it is used. For example, the phrase can be replaced with "lesser stage" or "secondary level" when referring to a less significant part of a project or process. Alternatively, "smaller portion" or "minor element" could be used when discussing a smaller component within a larger system. In a musical context, "minor part" or "secondary section" would be appropriate when referring to a less prominent part of a piece. Ultimately, the choice of synonym will depend upon the specific context in which the phrase is used, as well as the intended meaning and tone of the communication.