Seems this is an oft used expression in the music world, especially where there is reference to spirituality

Wanderer between worlds -
Anthropological perspectives on
healing rituals and music
Fachner, Jörg
Fachner, J. (2007) Wanderer between worlds - Anthropological perspectives on
healing rituals and music.
Music Therapy Today
(Online 18th July) Vol.VIII (2)
166-195.
Abstract
Discussions on music therapy theory often focus on the role of music in
ethnic healing contexts. This article explores aspects of biomedicine and
relational medicine in ethnotherapy approaches involving music, the role
of sound, trance, dance, sensory perception and rituals, and the way in
which concepts from ethnic traditions – informed by experience and
introduction – were traded through performance. This article describes
problems that emerge in defining and explaining experiential systems,
illustrate the pertinent paradigms with reference to the effects of music –
for example in the discussion of trance mechanisms – from the perspectives
of biomedicine and relational medicine, and interpret the role of
monochromatic and pulsing sounds, of rhythm and movement as a ritual
performance that is intended to induce alterations in consciousness, attitude
and behaviour. Ethno music opens the theoretical and practical
frame of reference for existing knowledge, for a wide anthropological
range of thinking and experience, for rituals where contents of significance
for the individual situation, according to biography and socialisation,
can be coded and decoded.

http://www.musictherapyworld.de/modules/mmmagazine/issues/20...

Wanderer Between Worlds: Geoffrey Smith profiles the controversial pianist and composer, whose spirit of adventure has made him one of classical music's most colourful figures.
http://www.bbc.co.uk/programmes/b007gbcf



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Note added at 27 mins (2009-01-28 17:18:21 GMT)
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From the British author of the Amazing Grace books comes a novel, the first in a trilogy, about a teen stricken with brain cancer who travels between two worlds. In modern-day London, Lucien Mulholland undergoes chemotherapy treatments, but when he falls asleep clutching a mysterious book his father has given him, he is transported, or "stravagated," to an enchanting 16th-century Venice-like city called Bellezza, in the country Talia. Lucien can return only if he can get hold of the book again. In this colorful other world, rich with court intrigues and magic, he feels vibrantly alive, as opposed to his pain-ridden days back in England; his hair has grown back and he eats with relish. Bellezza is also where, as "Luciano," he meets lovely 15-year-old Arianna and Rodolfo, who created the book that acts as Lucien's "stravagation" talisman. Rodolfo explains that a stravagante is "a wanderer between worlds," and also the history of this magical travel. Now the secret brotherhood dedicated to keeping the two worlds separate is being challenged by a faction with evil intent. Soon "Luciano" is caught up in their power struggle and learns there is a cost when one cannot stravagate properly. The Renaissance backdrop sets an elegant mood for the time-travel toggling. This complex, at times slow-moving and somber story line may disturb some middle-graders, but the novel will likely intrigue more sophisticated readers, especially with its undercurrents of sexual tension. Ages 10-up.
http://www.amazon.com/Stravaganza-City-Masks-Mary-Hoffman/dp...

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Note added at 29 mins (2009-01-28 17:20:44 GMT)
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And yet another context:

My Name is Jagdish Bhatt / Meine Name ist Jagdish Bhatt [FL 1181]
Jagdish Bhatt is a new Delhi slum dweller who, with brains, charm, and wit, repeatedly manages to overcome the narrow limits of his slum to work in Europe so he can feed his family of ten. He is a wanderer between worlds, a representative of the "globalization from below," where borders between the first and third worlds have become more porous and more rigid. Jagdish takes us through Kathputli Colony (Puppet Colony), where he lives. More than 3000 families live there, most of them artists: acrobats, snake conjurers, musicians, monkey trainers, magicians. In 2007 this unique colony will be torn down for the construction of a metro station -- a life-threatening situation for Jagdish. We meet a man who straddles extremes: while his puppetry is admired by a culturally aware public in Europe, in India he is just a face in a crowd. And while he is exposed to the seduction of money and sex in Europe, in India he wages a bitter struggle to survive. Gunter Heinzel, Germany, 2006, German, German, Hindi/Subtitles: English, 72 min, documentary film, DVD-ROM
http://www.osaarchivum.org/filmlibrary/browse/language?val=6...

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Note added at 1 day16 hrs (2009-01-30 09:27:44 GMT) Post-grading
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Thanks for the points, Martin