Pinyin of some characters in 李白's 塞下曲·其一

Question

I find different pinyins for this poem by 李白:

《塞下曲·其一》

五月天山雪，无花只有寒。

笛中闻折柳，春色未曾看。

晓战随金鼓，宵眠抱玉鞍。

愿将腰下剑，直为斩楼兰。

I think that this is the pronunciation, according to the meaning:

wǔ yuè tiān shān xuě ，wú huā zhǐ yǒu hán 。

dí zhōng wén zhé liǔ ，chūn sè wèi céng kān*。

xiǎo zhàn suí jīn gǔ ，xiāo mián bào yù ān 。

yuàn jiāng yāo xià jiàn ，zhí wèi zhǎn lóu lán 。

Sometimes, though, the words in bold have different pinyins. I wonder why (maybe to comply to some poetic rules? Or they are just errors?)...

Update

*As noted by @r13, the correct pinyin for 看 is kàn (kān was my mistake)

Answer 1

译文

• 到了五月，天山依旧白雪皑皑，没有鲜花，只有(only)地冻天寒。
• 虽然传来吹奏《折杨柳》(name of a musical - picking/folding willow)的笛声，却依旧看不到(could't see)一丝春色。
• 一早就随着战鼓声去搏战，到了夜晚也只能抱着马鞍打瞌睡。
• 希望能用我挎着的剑，像傅子介那样为国(for the country)除害，消灭敌人。

只 - zhī (同隻, 量词); zhǐ (衹, 仅仅 - only; just)

折 - zhē (倒腾, 折腾 - turn things side to side; do things over and over again); zhé (弄断, 折断 - tweak something to break off); shé (snap)

看 - kàn (see/look/watch); kān (守护，监视 - look/watch after; monitor; on constant guard)

为 - wéi (做，作，干，搞 - do; act; make); wèi (because; for; on account of)

Note: Except for the pronunciation of 看, all others agree with their respective explanations.