SELECT posts.ID, metaStartDate.*
FROM wp_posts posts
LEFT JOIN wp_postmeta meta ON (posts.ID = meta.post_id AND meta.meta_key = '_EventRepeats')
LEFT JOIN wp_postmeta metaStartDate ON (posts.ID = metaStartDate.post_id AND metaStartDate.meta_key = '_EventStartDate')
LEFT JOIN wp_postmeta metaRepeatsUntil ON (posts.ID = metaRepeatsUntil.post_id AND metaRepeatsUntil.meta_key = '_EventRepeatsUntil')
WHERE posts.post_type = 'tribe_events'
AND posts.post_status = 'publish'
AND meta.meta_value != 'once'
AND '2013-10-01 00:00:00' BETWEEN metaStartDate.meta_value AND metaRepeatsUntil.meta_value