Joni uses a lot of alternate tunings; that is, instead of tuning the guitar in the customary way, she tunes the strings to pitches of her own choosin… - Daniel Levitin

Myelin is a fatty substance that coats the axons, speeding up synaptic transmission. Myelanation... is generally completed by age twenty. Multiple sclerosis is one of several degenerative diseases that can affect the myelin sheath...

Memory strength is also a function of how much we care about the experience. ...If I'm playing an instrument I like, and whose sound pleases me in and of itself... caring leads to attention, and together they lead to measurable neurochemical changes. Dopamine, the neurotransmitter associated with emotional regulation, alertness, and mood, is released, and the dopaminergic system aids in encoding the memory trace.

In songbirds, it is generally the male of the species that sings, and for some species, the larger the repertoire, the more likely it is to attract a mate.