Final answer:
Double stopping is playing two strings at once, pizzicato is plucking the strings, tremolo is a quick up-and-down movement of the bow, glissando is gathering all pitches under the left-hand finger, and trill is rapid alternating between a note and one adjacent to it.
Step-by-step explanation:
1) The style of string playing that involves playing two strings at once is called double stopping. This technique is often used in orchestral music to create a rich and full sound. For example, in a violin concerto, the violinist may play a melody on one string while simultaneously playing a harmony note on another string.
2) When a stringed instrument is plucked instead of using a bow, it is called pizzicato. This technique is commonly used in genres like jazz and popular music. For example, in a jazz guitar solo, the guitarist may play a combination of picked notes and pizzicato notes.
3) The quick up-and-down movement of the bow is called tremolo. This technique is used to create a trembling or vibrating sound. For example, in a fast-paced orchestral piece, the strings may play tremolo to add intensity and energy to the music.
4) The style of string playing that involves gathering all pitches under the left-hand finger in one swooping sound is called a glissando. This technique is often used to create a smooth and sliding effect. For example, in a harp solo, the harpist may play a glissando to transition between different pitches.
5) The rapid alternating between a note and one adjacent to it is called a trill. This technique is used to add ornamentation and decoration to the music. For example, in a violin solo, the violinist may play a trill to embellish a melodic line.