“The End” Some say it's about chaos and change, the war and the apocalypse and certainly the Oedipus complex. “The blue bus" can be interpreted as a metaphorical vehicle that takes you to the road of life and love as opposed to the “ride the snake” as an hedonist, destructive lifestyle.
Others thought it represented the amount of free-spirited hippies and rebels versus government and corporate-consumer society in the sixties.
“When the Music’s Over” Morrison starts off by singing, "when the music's over, turn out the lights." This can be taken as a symbolism for when the “music” is over, death is the only option. This may sound dramatic, but is supported by other lyrics, such as "music is your only friend until the end" this could mean that, until your death, music is the only one friend who never turns the back on you.
“Indian Summer” Some say this song was dedicated to Jim's girlfriend Pamela Courson, while others think Jim was just describing a vibe from a southern California desert in the middle of an Indian summer autumn.
“Crystal Ship” This track was initially a poem in one of Jim Morrison’s notebooks, the title which he took from a Celtic legend in The Book of the Dun Cow. "Before you slip into unconsciousness, I'd like to have another kiss / Another flashing chance at bliss…" this could be viewed as having sex before going to sleep - “slip into unconsciousness”. And “another flashing chance at bliss” can be interpreted as one of the maximums pleasures a hedonist person can have, that is sex.
“Break on Through” Perhaps what the song symbolises the most is breaking through to the unknown, with the use of drugs. It's well-known that at the time Morrison was using LSD and other intoxicants to expand his mind.