What is the relationship, if any, between New Age music and New Age spirituality? Many people use New Age music as an aid to meditation, but that doesn't imply that either they or most New Age musicians would identify with the New Age spiritual movement.
Both the musical genre and the spiritual movement are difficult to pin down, because the definitions are both fluid and subjective. There are many different elements to New Age spirituality, and not everyone involved with one set of elements is equally engaged with all the others. You might believe in reincarnation, practice meditation, accept the concept of karma, and believe in a Goddess, without also believing in indigo children, the Maya 2012 prophecies, or alien abductions.
Similarly, you might enjoy either creating or listening to relaxing music based on drones and electronic sounds, without believing in any kind of spirituality at all. So what, if anything, is the connection?
I would suggest that the primary connection is a sense of optimism and well-being, combined with an expansive and open mood. Many New Age spirituality practitioners believe that the mind can be used to alter or control reality, and that positive, optimistic thinking has the power to cause good things to occur. Whether you believe this or not is a personal matter, but New Age music can certainly be conducive to that kind of worldview. You can think of the music as a soundtrack for a certain type of thinking and feeling, a certain way of perceiving (and trying to influence) reality.