Probably best solution to play with your own backing tracks.

[J.C.]

...at least that's how I do it

I use the spark amp only in one way, for playing together with backing tracks of my favorite songs.

For this i use also the Anytune app. There i can change the pitch of my favorite backing tracks, so that i not must retune my guitar for each song. I can also make the BT louder or quieter, just as i need it, so that it matches the volume of my preset for this song.
 
The program remembers these settings for each song. The volume and pitch of each BT is adjusted for every song individually and only once in Anytune.

So you have not to change the setting of the small music button in the right edge of the Spark amp. It can stay all the way up... ever.
Also my iPad volume is ever the same...at full, minus click twice, for the use at my home.

The output button on the amp needs only two positions, 2 o 'clock only for the presets with the real quiet amps and for all other presets it is all the time on 10 o' clock. All other knobs on the amp i don't need, because i play my favorite presets exclusivly over the app.

Once set, it's a very convenient way to play guitar.

Select preset, select backing track and press start, nothing else.

[Jeffrey22]

That is great J.C.

[DanL1553]

Thanks for the recommendation. This is a great find!

I got the Spark last week to replace my old Roland eBand 8 that used .mp3 files; I used a PC program called Song Surgeon to capture,manipulate and convert favorite songs into .mp3 backing tracks. I’ve spent the week learning the Spark App and trying to figure out how to deal with half-step-down-tuning songs like Yellow Submarine.

I just downloaded AnyTune on my iPad, watched the quickstart slides, and transposed Yellow Submarine in less than 5 minutes!

Thank you thank you thank you