Option A

MusicAssetList.cs

#region usings

using UnityEngine;
#if UNITY_EDITOR
using UnityEditor;
#endif
//using UnityEngine.UI;
//using UnityEngine.SceneManagement;
//using System;
//using System.Collections;
using System.Collections.Generic;

#endregion

#region Script
namespace ZeredaGamesEngine.Core.MusicListsExamples.Example3
{
    #region Attributes

    //[RequireComponent (typeof())]
    [System.Serializable]

    #endregion
    
    [CreateAssetMenu(menuName = "My custom button name", fileName = "NewInstanceOf_MyScriptableObject.asset")]
    public class MusicAssetList : ScriptableObject{

        public List<AudioClip> PlayList = new List<AudioClip>();

        /// <summary>
        /// Creates the general music list asset.
        /// </summary>
        /// <returns>The general music list asset.</returns>
        /// <param name="index">Index.</param>
        [MenuItem ("Window/Editor Tools/ZeredaGames/Game Making Editor Tools/Create Playlist-General Music", false, 1)]
        public static MusicAssetList CreateNewAsset ()
        {
            string AssetName = "Assets/Resources/Music/GeneralMusicList.asset";
            MusicAssetList asset = ScriptableObject.CreateInstance<MusicAssetList> ();
            AssetDatabase.CreateAsset (asset,  AssetName);
            AssetDatabase.SaveAssets ();
            EditorUtility.FocusProjectWindow ();
            Selection.activeObject = asset;
            return asset;
           
        }
    }
}

#endregion