EBook or book in mind that allows me just to learn the bare basics of whatever I need to know to start with LSDJ ()
i think you get 2 things mixed up... the tool and the Goal
LSDJ is a tool, you have to learn how to control it, as you would do for a guitar, flute or whatever
then > LSDJ manual!
Making Music is ''the goal'', which has to do with ''controlling the tool very well'' but not only...
The good news is that you do not need to get into boring/complicated stuff to get into it...
you have thousands of free site explaining very well the basics you will need for both understanding how music is made AND make your own
will that suffice?
depends on what you want to do...
for me absolute basics would be
- how Major scales work
- how chords are made
- what is the relation between scales and chords
in order to be able to built coherent melodies / harmonic backgrounds
but you can make entertaining sound without this also...