The text mentions a song about Rama. Are there any other songs or chants mentioned in chapter 19, perhaps about Shiva?

The provided passages from Chapter 19 do not mention any songs or chants related to Shiva. The chapter does, however, describe a specific personal experience involving the name of Rama. The author recounts deciding to perform continuous chanting of Rama's name and, upon setting out for darshan, hearing a beautiful song. As described in Chapter 19, this song included the lines, "I have found the collyrium of Guru’s grace, my brother; I do not believe in anything without Rama. Rama inside, Rama outside, I see Sita-Rama in my dreams." This was seen as a confirmation of the author's resolve and an example of the Guru's grace.