Centuries of doing wrong may make it common, but not necessarily correct. Sir Elton can only speak for himself, Chuck Berry sued The Beatles for using certain lines in Come Together. Speed and rhythm do not set mood nearly as much as the use of certain modes does. A part of the problem is the use of extra frets and capoes on dulcimers. I have seen too many people who fail to understand the characteristics of different modes partly because a few extra frets allows more than one mode to be played from a single tuning. Similarly, by moving a capo around all the modes are possible in one tuning. But each new position of the capo causes us to lose notes we played in the same tuning with different capo positions, or no capo at all. Not understanding the mode clouds the issue, we can't necessarily play the same song in different modal scales. Each mode has slightly different notes available. At the same time, for chord players,the notes available in a mode dictate what chords can be made using that modal scale. The harmonic elements of a mode are implied by the notes available, and by the locations of the half steps in that mode. This holds true whether we play chords or drones.Playing a diatonic instrument makes this very evident. Adding a capo or extra frets makes this much less easily seen. But when we take out notes from the melody, and substitute notes the composer didn't choose to use, we alter it into a new melody. ( I have done this myself, while singing, but only because I can't carry a tune in a bucket!) We do change the mood of the piece by changing the mode. Faster or slower is a change of arrangement. Using a rock setting rather than a country or jazz setting is a change of arrangement. Taking an ionian tune, and "playing" it using the lydian scale is not an arrangement, it's a new tune. If you use a new tune, for the sake of truth, say you have written a new tune. Anything less is bait and switch. Sir Elton may not mind if you put his words for Candle In The Wind to the tune from Ode To Joy, but if you can't get permission from Beethoven, maybe out of respect you should not go there. I'm not a composer, you won't find any songs of mine any where. I merely stated an opinion, based on not confusing other people who wonder why different peoples versions of the same song sound so different.
Paul

That's a great tip Ken! And the cats will like it too.
But I will be sure to give them my size for the free
With your wardrobe in it's current state !!
C'mon JK !!!