I read that I should get my peaks at -6dbfs and the rest at -18dbfs

so on my keyboard I can pound a single note and get -6dbfs at the peak and then the sustain will drop down to about -18

or I can pound a chord (which makes it much louder) so I have to adjust the input knob down

so should I use a chord to get my levels right?

is this the technique you use?