euphony

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Agreeable sound, especially in the phonetic quality of words.

from The Century Dictionary.

• noun Easy enunciation of sounds; a pronunciation which is pleasing to the sense; agreeable utterance.
• noun Harmonious arrangement of sounds in composition; a smooth and agreeable combination of articulate elements in any piece of writing.
• noun Synonyms Euphony, Melody, Harmony, Rhythm. Euphony in style respects simply the question of pleasing sounds in the words themselves. Melody respects the succession of sounds, especially as affected by the pitch appropriate to the thought and required by the arrangement of clauses. Harmony respects the adaptation of sound to sense. Rhythm respects the emphasis—that is, the succession of emphatic and unemphatic syllables. In music melody respects the agreeable combination of successive sounds of various pitch, while harmony respects the agreeable blending of simultaneous sounds of different pitch, the sounds in either case being from voices or musical instruments; thus, a song for children to sing must depend for its effect upon melody rather than harmony.

from the GNU version of the Collaborative International Dictionary of English.

• noun A pleasing or sweet sound; an easy, smooth enunciation of sounds; a pronunciation of letters and syllables which is pleasing to the ear.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A pronunciation of letters and syllables which is pleasing to the ear.
• noun Good phonetic quality of certain words.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun any agreeable (pleasing and harmonious) sounds