What's the difference between hymn and hymnologist?

Hymn

Definition:

(n.) An ode or song of praise or adoration; especially, a religious ode, a sacred lyric; a song of praise or thankgiving intended to be used in religious service; as, the Homeric hymns; Watts' hymns.
(v. t.) To praise in song; to worship or extol by singing hymns; to sing.
(v. i.) To sing in praise or adoration.

Example Sentences:

(1) A truck stopped on a street corner, blaring martyrdom hymns throughout the cavernous lanes and alleys of the party's heartland.
(2) As the hymns faded Francis made a now familiar appeal in English: “Please,” he said, “I ask you: don’t forget to pray for me.” It was his last scheduled event in New York.
(3) Many wept, wiping tears off their faces as the melancholic tunes of the hymns reached them through loudspeakers.
(4) He has also covered an old Scottish folk song, 'Hymn Of The Whale', as well as a fearsome semi-industrial track in the company of the erstwhile drummer from Nine Inch Nails.
(5) In East Germany this was our hymn,” says one man.
(6) A hymn to the depravity of Edinburgh that balances the noble pursuance of art.
(7) He was not a Christian then: he had had the conventional upper-class socialisation of tedious hymns and meaningless sermons, which normally functions as a vaccine against religious fervour.
(8) !” singing hymns and other songs The women, who are a range of ages, have travelled from across Gauteng province and are and saying a prayer ahead of a planned march in the city centre.
(9) Chanting battle hymns, they jogged past buildings still pockmarked by clashes with US forces who occupied the area in 2008 and had fought running battles with the Mahdi army for most of the nine years that they remained in Iraq.
(10) A hymn of praise, and a word of warning,” the book has been compiled by two titans of pragmatic ecology, Nigel Holmes and Paul Raven.
(11) How can he, of all people, hymn bourgeois notions such as commitment and conjugal felicity?
(12) She was undergoing a bone-marrow transplant for leukaemia when I was writing Battle Hymn of the Tiger Mother and I went through a life-questioning crisis.
(13) The song – which cannot be described as great art - like many National Anthems including our own, is strident and solemn, and could be hymn.
(14) John Kampfner: Clegg has an opportunity now to strike out After Chairman Mao and the 1950s hymn book , the Liberal Democrats had the chance of offering something more modern and enticing than their rivals.
(15) The familiar biblical words, the quavering congregation working its way through Victorian hymns, the priest, who often has never met the deceased: all these deaden and distance.
(16) I know the hymns and I know the prayers and I know the good done by many Christians in the act of witness.
(17) The point is that Marine can have a clear-out, and everyone will now (more or less) sing from the same hymn sheet: hers.
(18) In Battle Hymn …, she writes that she was determined "not to raise a soft, entitled child – not to let my family fall".
(19) We stand up a lot in church, albeit tardily for the drearier hymns.
(20) There was even a chant of "Attack, attack, attack" from the Stretford End as the game kicked off as if in anticipation of the shackles of unadventurous football being thrown off, plus any number of favourite hymns to Giggs and Paul Scholes.