The Balrog’s exact size and shape is somewhat ambiguous, with Tolkien’s ideas appearing to have changed over time and from one story to another. Believe it or not, the question of whether a Balrog does or does not have wings is one of the most fiercely debated subjects amongst Tolkien fans. Read the arguments here.
The most probable influence for Tolkien’s Balrogs are the demons of religion and folklore; evil spirits or creatures from Hell. According to some traditions, a demon can be summoned and controlled, which is how warlocks and witches gain their powers. In Christian demonology, some demons are considered to be fallen angels, an idea that resembles the corrupted Maiar of Tolkien’s creation. Demons are often portrayed in artwork in a similar manner to Balrogs, with horns, glowing eyes and bodies made of flame, carrying whips or swords.
The Secret Fire is the life-giving power that Ilúvatar gave to the world, and Anor is the Sindarin name for the Sun. Gandalf is a servant of this power because he is one of the Maiar, and has been sent into Middle-earth to guide its inhabitants in the coming war.
Udûn (also known as Utumno) was Morgoth’s (then known as Melkor) fortress in the north of Middle-earth. It is also the name of a valley in north-west Mordor. It was at Utumno that Melkor began to corrupt creation, bringing back captive elves and breeding evil creatures. In the Years of the Trees, the Valar decided to save the elves and stop Melkor’s evil. In the ensuing war they destroyed his fortress Utumno and took Melkor back to Valinor as prisoner.
The Lord of the Rings inspired the composer Jonathan Peters to pay tribute to Tolkien with a symphonic version of the novel. This movement portrays the timelessness and beauty of Lothlórien:
Peters' album, The Journey of the Ring, contains an hour of music that covers all the major chapters, peoples and places in The Lord of the Rings. Here, accompanied with some great images of Middle-Earth, is a sampler of the album:
A version of the Lay of Nimrodel by YouTube user Endakil:
Inspired by the same song, the band Rivendell have recorded a very different version: