Well, Charlotte, tone is the mood your mind sends to envelope your body in buttercup petals, moths wings or thorns. The rhythm, by contrast is the beat to which your limbs move and your shoulders and pelvis gyrates. When a pictures clicks to the next position, it is best to also hit a beat in the rhythm of the music, just like the lips of a singer are in synch with the words of the song. We are expert and intuitive and we can easily see a person who dances well, every sinew of the body in line with the beat and melody as opposed to the awkward movements of the iconic nerd with 3 pencils, a comb and a slide rule in his shirt pocket, who has no apparent sense to move his body, apart from bobbing up and down!
The two parts of the 3 part equation you have aced: namely the image content and the emotions of the music, but the rhythm, (of the movement of the sequential changing of your slides and their content), does not match the music in any measure I can currently fathom.
This is an area of movie editing that takes up as much effort, experience, knowledge and skill as either the creation of the pictures or the composing of the music itself. Also, we're so used to seeing perfectly timed matching of changing images with music in every ingle advertisement and each fraction of a scene on any TV or theatrically released movie. This appreciation is now instinctive! We recognize any lack of synergy between pacing of slides or parts of slides and the timing of beats in accompanying music. If there's a mismatch, we can get exiled from the magical and creative universe your work begs us to enter!
My son has worked on major soundtracks, so I have personal knowledge of this set of hard one skillsets needed for adding music to imagery. One does not want to alter the perfect images or the well chosen music, but one can use certain tricks to make it appear that the two are in synch, at all times.
One can have more slides, each being a portion of thevwholebor the whole again. One can zoom in or out or walk over an image detail by detail as the music directs the pace.
I take this effort to challenge you to move from interesting, wonderful and praiseworthy to a level of excellence that demands folk send everyone they know to your site to feed on your delightful offerings.