As you watch this brief video below at a Solemn Sung Mass in the Extraordinary Form at Ireland's recent Eucharistic Congress, please note one of the so-called "problems" of the EF Mass when sung according to the 1962 missal and not its minor 1965 revision and it is this:
There are two Masses going on simultaneously, one sacramental and the other faux. The Sacramental one is only partially sung by the priest but what is sung by the choir, the priest recites to himself and it is his recitation that is important, not the choir/congregation's sung parts, the faux parts.
For example in the brief video below, the choir has sung before this video clip the official Introit as the priest and servers recite the prayers at the foot of the altar, then the priest approaches the altar kisses it, incenses it as the choir/congregation move onto the Kyrie, but the priest lags behind the faux Mass. After incensing the altar, he goes and reads the Official Introit (Keep in mind this is a sung Mass!) Then he recites the Kyrie at the Epistle side of the altar and remains there until the Faux Mass Kyrie is completed, which takes longer than his recitation of the Kyrie, the true Mass.
Of course we do not hear the faux Gloria sung, but rest assured that after the priest introduces it in a chant fashion, the choir picks it up and he recites it while the faux Mass is sung. Of course the recitation of the true Gloria will be shorter than the faux Gloria, so the priest and his ministers will sit down to wait it out. Then he will stand, return to the altar and actually chant the Collect.
The 1965 reform of the Tridentine Mass, while remaining the Tridentine Mass, did away with the Faux Mass and made it a part of the Sacramental Mass in that the priest is directed by the rubrics not the recite any part of the Mass that the Choir sings, but to join in the singing of that part with them, thus unifying the Sacramental Mass and Faux Mass into one Mass. Yes, Virginia, this is a liturgical abuse in this 1962 missal's sung Mass and it is out in the open in the video below, but not viewed as an abuse because the abuse is beautiful, but non-liturgical, created a faux Mass and a Sacramental Mass, while not a clown Mass, is nonetheless a Mass that needs revision.
Yes, the EF Mass, the 1962 one, needed and needs reform.