Know the teachings that Ravana gave to Laxman on his deathbed

Valmiki describes Ravana as the greatest devotee of Shiva. In many folk versions of the epic, such as Ram-kathas and Ram-kiritis, we are informed that Ravana composed the Rudra Stotra in praise of Shiva, the ascetic-God.  

He designed the lute known as Rudra-Veena using one of his 10 heads as the lute's gourd, one of his arms as the beam and his nerves as the strings.