Dynamics

Intensity is one of the properties of sound: how loud or soft it is. In music it does not stand still. A passage starts softly, grows, bursts, fades. The art of grading that intensity in performance is called dynamics (Lacerda 1966, ch. XVI).

Blatter notes that dynamic markings are far less precise than the notation of pitch and duration, and far newer too: they only began to appear in scores in the seventeenth century (Blatter 2007, part 1, art. 6).

Piano and forte

It all starts from two Italian words. A passage played with little intensity is piano, soft; with a lot, it is forte, loud (Lacerda 1966, ch. XVI). In the score they appear abbreviated, p and f, and usually sit below the staff. In vocal music, where the words go underneath, they often go above (Blatter 2007, part 1, art. 6).

Hear the passage

Listen: the same notes, first soft, then loud. A marking holds from the note where it appears until another one comes along.

The scale

Between the two extremes there are steps. Repeating the letter goes further; with mezzo, meaning half, it lands in between.

Sign	Name	Loudness
ppp	pianississimo	as soft as possible
pp	pianissimo	very soft
p	piano	soft
mp	mezzo piano	half soft
mf	mezzo forte	half loud
f	forte	loud
ff	fortissimo	very loud
fff	fortississimo	as loud as possible

Hear the passage

The scale can stretch further still. Med records extremes such as a pppppp in bar 160 of Tchaikovsky's Sixth Symphony, and points out that not every instrument reaches every step across its whole range: a ppp in the oboe's low register is almost impossible (Med 1996, ch. XXXIII).

Loud compared with what?

An f has no fixed volume. Blatter is blunt: there is no standard for what a forte or a piano is; it is always a matter of interpretation, and depends on the size of the room and the style of the music (Blatter 2007, part 1, art. 6). Med reaches the same conclusion: physics measures intensity in decibels, but in performance it is not measured, it is compared (Med 1996, ch. XXXIII). The f of a solo guitar and the f of a full orchestra are each loud in their own world.

That is why the markings take words that adjust the degree: poco f, a little loud; più p, softer; meno f, less loud; sempre pp, always very soft; p subito, suddenly soft, without preparation.

Growing and fading

Loudness also changes gradually. To grow louder, the score says crescendo (cresc.); to grow softer, decrescendo (decresc.) or diminuendo (dim.). Instead of the words, two angle-shaped signs, the hairpins: opening to grow, closing to fade.

Hear the passage

Hear the passage

Lacerda prefers the signs to the words, because they show the gradual growth or fading more clearly; and when the change spans several bars he recommends a dotted line after the word, to make clear how far it goes (Lacerda 1966, ch. XVI).

Sudden reinforcements

Sometimes the change is not gradual but a single note. Sforzato, abbreviated sf, asks for a sudden accent on that note; the following notes return to the passage's loudness (Lacerda 1966, ch. XVI).

Hear the passage

Forte-piano, fp, looks similar and is not. It attacks the note loud and asks for piano straight away, for that note and the ones after. Lacerda insists on the difference: sf accents only the note; fp accents the note and changes the loudness of what follows.

Hear the passage

Like the accents in the topic on articulation, sf is proportional to the overall loudness: in a soft passage it should be gentler than in a loud one.

Here the books differ in detail. Lacerda deals only with sf. Blatter lists sforzando and forzando as separate markings (Blatter 2007, part 1, art. 6). Med goes further and separates sf, fz and sfz, each with its own accent sign and range of loudness (Med 1996, ch. XXXIII).

What comes next

Dynamics and articulation are the two layers of expression the score writes over the notes. From intensity, notation turns to the one property of sound still left: timbre, which the score indicates by naming the instrument or the voice.