Melanie sits next to 4 phonetic neighbors — Melody, Melanie, and Elanie are the closest matches by sound. Most share Melanie's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"dark-complexioned, of dark appearance"
"of noble lineage"
"grace in Igbo language"
"epithet of Demeter, goddess of grain"
"light, illumination"
"Jupiter's child, Jove"
"truth, genuine"
"ivy plant, climbing vine"
"great, noble (from botanist's surname)"
"born at night"
"freedom, grace"
"messenger of God; angel"
"defender of the people"
"wren bird clearing"
"noble, free-born youth in service of the temple"
"high, exalted"
"gentle, pure one"
"stone of the flank"
"seller of scarlet cloth"
"birdlike, resembling a bird"
"heaven (spelled backwards)"
Similar sound: These names share phonetic patterns with Melanie — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Greek origins, giving them the same cultural heritage as Melanie.
Rhythm: Melanie is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.