1.and my love will dance to the sound of the harp and the violin. She will dance so lightly that her feet will not touch the floor.

【难句释义】my love will dance following the melody of the harp and the violin.

【难句解析】dance to:随（音乐）起舞；dance with和某人跳舞

2.But with me she will not dance, for I have no red rose to give her," and he flung himself down on the grass...

【难句释义】"But she will not dance with me, because I haven't a red rose to give her,"and then he threw himself down on the grass disappointedly.