1962 Missal, Mass of John XXIII are the Extraordinary Form(or Traditional Latin Mass)
The Ordinary Form of the Mass, doesn’t really have a concept of Low Mass, High Mass or Solemn High Mass, because the rubrics are in such a way that you can kinda, “mix-n-match”. So you can have incense, but the mass is all spoken, or you can have the mass all sung, but no incense, you can have a deacon but no singing, etc.
You’ll hear a OF Mass, sung in Latin, with incense, bells, and Chant and Polyphony etc. called “Solemn”, I suppose it is, but there really isn’t anything in the Rubrics indicating that this means “Solemn” in the OF.
The Extraordinary Form on the other hand, the rubrics are more detailed and “strict”. There are 4 expressions of the Mass.
Low Mass( also called Missa Lecta, Missa Privata, dialogue mass, etc.) Is a mass in which the prayers are read not sung, there is neither Deacon nor Subdeacon, there’s only 1 or 2 Acolytes(Altar Servers), two candles are lit on the Altar. There is no incense, or Solemn procession, with Candles and Crucifix. The Priest comes in with the Sacred Vessels There can be a choir, but they don’t sing any of the propers, instead they sing Hymns. Since the 1940’s the congregation has been encouraged to reply along with the Altar Servers at certain responses, but this isn’t mandatory, and may vary from parish to parish, usually these are called “Dialogue” Mass, but they’re still ultimately Low Mass. This probably, the most common form of Weekday worship for EF communities, or Sunday Worship for Mission EF communities.
High Mass( also known as Sung Mass, Missa Cantata) this is a Mass in which the audible prayers are sung, the Propers and Ordinary are sung by the choir too, there are usually 4 or more Altar Servers, there’s incense, six Candles are lit on the Altar, the Sacred Vessels are on the Altar. But there is no Deacon and Subdeacon, so the Priest sings both the Epistle and the Gospel. This is probably the most common form of Sunday Worship for established EF communities.
Solemn High Mass, is everything I described in the High Mass, plus a Deacon and Subdeacon( usually Priests who vest"down"), with the exception that the Sacred Vessels aren’t present on the Altar, but are on the Credence table until the Creed, when the Subdeacon transfers them to the Altar. Common form of Worship on Solemnities, anD Feast Days, for well established EF communities. Maybe regular be Sunday Worship for other some.
Finally we have the, Pontifical Solemn High Mass, this is the fullest, and ideal, expression of the Mass, in the EF. It includes everything described above, plus we have Deacons of the Throne, the Throne( the seat of the Bishop), and sometimes an Assitant Priest. Also the Bishop, I believe, sings the Collect and Post Communion prayer from the Throne, not the Altar.