Music Chords: Paste richtext1 lines and copy to richtext2 selected lines

[AntonyCode]

RICHTEXT1:
Am___E7
On a dark desert highway, cool wind in my hair
G__D
Warm smell of colitas rising up through the air
F__C
Up ahead in the distance, I saw a shimmering light
Dm
My head grew heavy and my sight grew dim

RICHTEXT2:
On a dark desert highway Cool wind in my hair
Warm smell of colitas Rising up through the air
Up ahead in the distance I saw a shimmering light
My head grew heavy and my sight grew dim

There she stood in the doorway
I heard the mission bell
And I was thinking to myself
"This could be Heaven or this could be Hell"

How to copy lines [0][2][4][6] -- To the other lyrics, whitout delete them.

                string[] line = Clipboard.GetText().Split('\n');   // richtext1 copy lines to clipboard
                //string[] line = richTextBox1.Lines;
                //string line1 = richTextBox2.Text;
                string line1 = richTextBox2.SelectedText;

                richTextBox2.Text = line1.Replace("\n", "\n\n").Insert(0, "\n"); // Add new empty line in richtext 
                string[] line2 = richTextBox2.Lines;


                RichTextBox richText = new RichTextBox();

                for (int i = 0; i < line.Length; i++)
                {
                    int x = i;

                    if ((x % 2) == 0)  // define odd line
                    {
                        //string l1 = line[i];

                        richText.Text += "\n" + line[i];
                    }
                    else
                    {
                        richText.Text += "\n" + line2[i];
                    }
                    richTextBox2.Text = richText.Text;

It works but deletes all richtext2
Thanks for help