Phoenix Abbo

A descending fifths sequence is a common compositional technique used by composers from the eighteenth century to expand a simple melodic or harmonic idea. A typical descending fifths sequence is executed when a short melodic phrase is played over a note (or a collection of notes with emphasis on one in particular) in the bass. The next phrase will virtually be an exact copy of the previous phrase and accompanying bassline, except that it will have been transposed an interval of a diatonic fifth downward or a diatonic fourth upward (either direction will result in the same pitches). In other words, the second phrase will begin at the pitches that would result from moving the first phrase down four notes (or up three notes) within the diatonic scale that the music is in. This process often is repeated multiple times in a single section of the music.

Drottningholms Barockensemble, conducted by Jaap Schröder

In terms of texture, eighteenth century music often will often incorporate a single melodic line that is accompanied by a more rhythmically simple harmony. This could be described as melody-dominated homophony. With this effect, the listener is drawn solely to the melodic line, with accompaniment only serving to enhance and support the melody. In this example, taken from the beginning of the third movement, “Vivace,” of Johan Helmich Roman’s Symphony No. 3 in B-flat Major,  the violin I section carries the active melody, while the rest of the strings and the harpsichord play very simple lines that are often in rhythmic unison with each other and only outline the harmony of the music. This texture helps bring attention to the melody of the violin I section while while emphasizing the harmony of the piece.

Chamber Orchestra of the Budapest Philharmonic Society
Miklós Erdélyi

When at least two musical parts are performed at the same pitch and rhythm at the same time. 

This excerpt includes violins, violas, basses, oboes, and horns. They begin playing polyphonically, and 7 seconds into the excerpt they play in unison.

Orchestra Della Toscana; Donato Renzetti (Conductor)

An anacrusis is an introductory note or group of notes that is played before the downbeat of a phrase or section of music. The first note heard in the provided recording is the anacrusis.

Chamber Orchestra of the Budapest Philharmonic Society
Miklós Erdélyi

A melodic sequence occurs when a motive repeats at a higher or lower pitch. Melodic sequences are used primarily for elaboration and expansion of a melody.

This excerpt includes two melodic sequences back-to-back, the first descending in pitch and the second ascending. The excerpt is taken from the Finale of "Mythologische Operette" by Michael Haydn.

Orion Chamber Orchestra

The definition of a melody is a sequence of single notes that is musically satisfying. Melody is built upon many concepts, such as rhythm, shapes, color, timbre, etc. In this case, the melody is passed around the diferent parts of the ensemble. First off, the background has the 8th note part on the Violoncello and the high voices take the melody with the quarter note motion. The shape of each part of the melody keeps moving upward, depending on the key. After that, the violins take the 16th note part and pass the emphasis on melody to the rest of the ensemble. Winds play strong downbeats, along with the lower voices of the strings.

Bay, Rudolf, Bombelle, Toke Lund Christiansen, Domenico Cimarosa, Inger Dam-Jensen, Gaetano Donizetti, Dorthe Dreie; Hong Kong: Naxos Digital Services Ltd.

In Galant style music commonly there was only on melodic line present at a time, often accompanied by fast rhythmic harmony. In this example the Flute has the melody while being accompanied by the strings. After several seconds, the two switch roles.