How do I get a song to play in 3/4 time or waltz style

[pdxdjazz]

Any song will play in 3/4.
Simply change the time-sig to 3/4 (or whatever you want) USING THE IN-APP EDITOR.
It's the pencil icon.
If you edit a DUPLICATE, the original version will remain unchanged in your library.
Your edited version will automatically have a number added to the title.
You can instead of the number, edit the title to say <title>waltz.
A song with standard sized bars (4 spaces each) can usually also play as a waltz without problems.

As to additional player styles...you will only have the on-board styles that are available for your app's version.
You may have to download the newest app version to have access to all the (additional?) player-styles.
Older devices may not be compatible with the newest app version.
It's also possible that the style(s) you want aren't available (yet).
)BOB