The Maharil haKodesh says that these are MiSinai tunes. They’re so kadosh that it’s as if they go back to Har Sinai. One should not change these tunes. The most important are the tunes for the barchu for Maariv and Shachris, the tune for the Half Kaddish of Musaf, Avos, Kedusha, Neilah nusach, and the Avodah shel Yom Kippur. The chatimah of each bracha is also MiSinai.
The well known tunes for Areshet Sefateinu, Yimloch, Zochreinu, Kevakaras, etc. are written by great chazzanim of the past 100 or so years (Kwartin, Goldfarb, Zivlin, Rosenblatt, etc.)