Symphony sits next to 3 phonetic neighbors — Harmony, Melony, and Tiffany are the closest matches by sound. Most share Symphony's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"harmony of sounds, consonance"
"from the marshes"
"blue"
"to hold dear, to treasure"
"she who brings happiness"
"beloved, cherished"
"woodland clearing"
"sun gift (Sunniva variant)"
"ardor, enthusiasm, passion"
"city of Odysseus"
"Christmas, born at Christmas"
"praised"
"rocky clearing"
"gentle, beautiful"
"from the elder tree grove"
"timid (from Bilhah)"
"diminutive of Dorothy, beloved pet name"
"brave in battle, vigilant in war"
"Jay + lake (modern American coinage)"
"from the Lorraine region of France"
"rival, industrious"
Similar sound: These names share phonetic patterns with Symphony — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Greek origins, giving them the same cultural heritage as Symphony.
Rhythm: Symphony is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.