Music Speed Changer can remember your preferred settings for each one of your tracks. In the app main menu, under pitch and tempo, click “On track change” and check the last option, “Save and restore adjustments per track”. This will make the app remember the last pitch and tempo settings used by each track. Below are the steps to change the settings to enable Music Speed Changer remember each track's pitch and tempo settings.
Remember Pitch and Tempo Settings for Each Track
Open the app main menu
Select Settings
Tap on Pitch and tempo
Tap on "On track change"
Check "Save and restore adjustments per track"
Have the Same Pitch and Tempo for All Playing
Open the app main menu
Select Settings
Tap on Pitch and tempo
Tap on "On track change"
Check "Keep adjustments from last track"