Thought Forms is a book by Annie Besant and C.W. Leadbeater that studies the nature and power of thoughts. It states that thoughts have two effects: "a radiating vibration and a floating form". Thought forms are divided into three classes:That which takes the image of the thinker.That which takes the image of some material object.That which takes a form entirely its own, expressing its inherent qualities in the matter which it draws round it.The effect of music, emotions, and colors on thought forms is also described in the book. The effect of the music of Mendelssohn (No. 9 of his "Songs without words"), Gounod (Soldiers Chorus from "Faust") and Richard Wagner (Overture to "The Meistersingers") is analyzed. The music of Wagner produced a "marvellous mountain-range" on the thought forms.