For as long as I can remember, I’ve been telling students that they must play with their left hand finger tips. This is the strongest position and yields the best sound.
The reality is, however, not so clear cut.
The Easy Doctrine
If there’s one overarching philosophy I try to preach on the classical guitar blog it is to be profoundly lazy. That is, do the least amount of work required to achieve the desired result.
To that end, the left hand fingertips advice is not set in stone. There’s a variety of situations in which playing with the fingertips less than perpendicular makes things easier.
A Few Examples
Reaching the lower strings using more of the fingertip pads can make things easier. Especially notice that the first and fourth fingers tend to be more on their pads (a consequence of them being a bit shorter on most people).
In the same way reaching bass notes will holding down notes on the treble strings sometimes necessitates a bit of pad playing. Notice the fourth finger in this chord shape from the Coda of Giuliani’s Variations on Folies d’Espagne.
Our muscles are the strongest and most efficient in their mid-range of movement. Sometimes playing more on the pads of the fingers lets us keep finger joints more in the mid-range. Check out this angled hand position. The fourth finger, once again, can be a on its pad a bit.
Another, often overlooked use of pad playing in the hinge bar. Doing a hinge bar requires that the first finger remain more on its pad then fingertip.
Where On the Fingertips Anyway
Not all fingertips will be straight on the strings. A straight wrist position puts the fingers one and four on their outside edges.
As I said above: make it easy. If using more of the pad does that without compromising sound and clarity, do it! If not, trash it. This is not an excuse to play sloppily, but something to think about the next time you work through a piece.