Don's quote: "I have a nice audio (.wma) file of a great piano solo. I want to add drums and strings. Unfortunately, these tutorials are not much help in this instance. Can you or other experienced RB users get me started in the right direction please?"

Don, in RB, the sequence to add the audio file and then add additional instruments is as follows:

Import your wma file into RB
Open the Audio Chord Wizard,
Choose existing song (which is your audio wma piano file)
Run ACW to determine key, create a tempo map and input the chord progression into the CF page of RB.

Choose a blank track to begin adding RealTracks, Midi, Super Midi or live vocals or instruments.

Be Careful!! it quickly becomes addictive.
BiaB Ultra Pak+ 2020:RB 2020 Build 1. Dell Inspiron AIO Desktop; Windows-10-64 bit, 7th Generation AMD A9-9425 Processor Five Core 3100 Mhz and 16GB DDR4 Memory.