While Asha's homage to the four ghazal greats - Farida Khannum, Mehdi Hasan, Ghulam Ali and Jagjit Singh - entitled "Asha" is ready for release, the Lata Mangeshkar album with original ghazals composed by her protégé Mayuresh Pai is in the process of being completed.
Asha has an edge time-wise since her album is up for release before her sister's. But there's no sense of rivalry between the two sisters any longer.
Says Lata with a smile: "I'm so glad Asha is doing a non-film album. We both need to build our creative energies in areas other than films. Asha has always been a very good ghazal singer.
"Who can forget her songs in 'Umrao Jaan', or R.D. Burman's 'Aur kya ahde wafaa hote hain' (from the film 'Sunny')? I'm sure her album will be special."
Asha reciprocates the compliment. "Didi to didi hain! Whatever she does is bound to be special."
Says Lata: "I've earlier worked with Mayuresh on an album of (former prime minister) Atal Bihari Vajpayee's poems. The way he tuned the blank verse and provided me comfortable spaces to sing gave me the confidence to work on a whole album of ghazals with him.
"I've always enjoyed singing ghazals, both in films and otherwise. Everyone knows my ghazals for Madan Mohan. But my non-film renditions of Ghalib's ghazals composed by my brother (Hridaynath Mangeshkar) have always been a favourite.
"Then there was 'Sajda' in the 1990s which I did with Jagjit Singh. I hope to capture at least some of that feeling in my new ghazal album."
Asha, a dexterous ghazal singer, has sung some of her choicest ghazals for Khayyam in "Umrao Jaan" and "Ahista Ahista". She also did a celebrated album with Ghulam Ali called "Meraj-e-Ghazal".
"Some years ago I recorded an album with Khayyam for Music India. That somehow didn't find the right marketing and was lost in the crowd of albums. Hence I've switched to Sa Re Ga Ma HMV for my new album. I trust they will do justice to it."
Interestingly, Sa Re Ga Ma HMV has traditionally been a company that devoted itself to Lata's repertoire.
Says Asha: "Times change, tunes change. Today I'm comfortable working with them. I hope 'Asha' will be a new beginning for both me and the music company."
As both the singing legends prepare to put out ghazal albums, listeners have much to look forward to.