iOS label not start from the top - ios

Question

My controller allows me to show a text from a song inside a label but I don't know why the gravity of the text is focused at the end. When I want to see the text I always see the song like it's already scrolled. I want to start the song from the top and then scroll it or zoom it.
Every time I want to see a song that is longer than the page I see like it's already scrolled, but if I want to see a song that is shorter than the page it works correctly. How can I fix it??
Here is my code:
import UIKit
class DettaglioCanti: UIViewController {
var dettaglioCanzone: VociMontagna? {
didSet {
configureView()
}
}
var valoriPassati: VociMontagna?
#IBOutlet weak var tv_titolo: UILabel!
#IBOutlet weak var tv_artista: UILabel!
#IBOutlet weak var tv_testoCanzone: UITextView!
#IBAction func btt_note(_ sender: Any) {
startPopUp()
}
#IBOutlet weak var btt_note_2: UIButton!
var pinchGesture = UIPinchGestureRecognizer()
override func viewDidLoad() {
super.viewDidLoad()
configureView()
pinchGesture = UIPinchGestureRecognizer(target: self, action:#selector(pinchText(sender:)))
tv_testoCanzone.addGestureRecognizer(pinchGesture)
let range = NSMakeRange(tv_testoCanzone.text.count - 1, 0)
tv_testoCanzone.scrollRangeToVisible(range)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#objc func pinchText(sender: UIPinchGestureRecognizer) {
var pointSize = tv_testoCanzone.font?.pointSize
pointSize = ((sender.velocity > 0) ? 1 : -1) * 1 + pointSize!;
//Definisco i limiti dello zoom per il testo
if (pointSize! < 13) {pointSize = 13}
if (pointSize! > 42) {pointSize = 42}
tv_testoCanzone.font = UIFont( name: "arial", size: (pointSize)!)
}
func configureView() {
if let dettaglioCanzone = dettaglioCanzone {
if let tv_titolo = tv_titolo, let tv_testoCanzone = tv_testoCanzone, let tv_artista = tv_artista {
tv_titolo.text = dettaglioCanzone.titolo
tv_artista.text = dettaglioCanzone.artista
tv_testoCanzone.text = loadFile(file: dettaglioCanzone.nomeTesto)
if (dettaglioCanzone.nomeNota == "0") {btt_note_2.isHidden = true}
}
}
}
func loadFile(file name:String) -> String {
if let path = Bundle.main.path(forResource: name, ofType: "txt") {
if let contents = try? String(contentsOfFile: path) {
return contents
} else {
print("Error! - This file doesn't contain any text.")
}
} else {
print("Error! - This file doesn't exist.")
}
return ""
}
}