Step 1: Understanding the Concept:
The question asks to identify the specific type or pitch-variety of Mridangam that is suitable for accompanying female vocalists.
Step 2: Detailed Explanation:
The pitch of a Mridangam needs to be tuned to the tonic note (Shruti) of the main performer. Since female singers generally have a higher vocal range and sing at a higher pitch (typically from G to B, known as 5 to 7 kattai/shruti), a Mridangam that is smaller and can be tuned to a higher pitch is required. This variety is known as 'Kappi' Mridangam. A lower-pitched Mridangam, used for male vocalists, is known as 'Kutchi'.
Step 3: Final Answer:
The Kappi variety of Mridangam is used to accompany female singers.