Varnams appear to have grown in volume over the years. The "Sangita Sarvartha Sara Sangrahamu" of Veena Ramanujayya has only 12 in its 1885 edition. There are 25 in "Pallavi Svarakalpavalli" (1900) which has the compositions of Veena Kuppayyar and Tiruvottiyur Tyageyya. There are 40 varnams in "Sangita Sampradaya Pradarshini" of Subbarama Dikshitar (1904). In "Varnasagaram" by TK Govinda Rao (2006) there are 500 varnas and in "Tana Varna Tarangini" of BM Sundaram there are 806 varnas, and Karnatic.com database includes 1457 varnas.
Structure of Pada and Tana varnas is the same. Generally, it is accepted that Tana varna has no sahityam for Muktayi and Ettugada svaras, and Pada varna has. However, the presence of sahityam for Muktayi svara and Ettugada svaras is not very reliable criteria of classification of varnas in Tana and Pada. Earlier, both types of varnas included "full set" of sahityam, and even Anubandham, which could be regarded as being part of Ettugada Pallavi to be sung in conclusion of the second portion. For instance, there Tana varnas with sahityam for Muktayi and Ettugada svaras and Pada varnas without ones.
For instance, there Tana varnas with sahityam (according to Dr. Durga): "Dari teliyaka" in Darbar, Ata by Patnam Subrahmaniya Iyer, and "Dani Korikenu" in Vasanta, Jampa by Ramnad Srinivasa Iyengar.
According to S.R. Jayasitalakshmi, there are four Ata tala Tana varnas of Subburama Dikshitar, including "Sri rajadhiraja" in Balahamsa; "Sri rajivakshadi" in Edukula kamboji; "Sri rajarajarajamanna" in Atana/Purnacandrika; and "Sri maharajadi" in Atana, with Sahityam for all svaras.
Pada varnas without sahityam for Muktayi and Ettugada svaras include "Rammanave" in Hindolam, Rupakam by Ramaswani Dikshitar and "Roopamujuchi" in Todi, Adi by Muthuswani Dikshitar (through, other Chowka varnas of Ramaswami Dikshitar do have sahitya for all the section, for instance "Sami nine" in Sriranjani" and "Ela nannechevu" in Purnacamndrika).
The major difference between the two types of varnas is the tempo, as Pada varnas are set to Vilamba kala and Tana Varnas are majorly set in Madhyama kala. Thus, the term "Chowka varnam" is used as synonym of "Pada varnam." Subbarama Dikshitar mentions Lakshanas of Chowka and Tana varnas in his work "Sangita Prachina Paddhati" as follows:
"Chowka varna resembles a pada, i.e. Sahitya composed with Sringara Rasa and is in slow tempo. Muktayi svara should have double the number of avartas then that of anupallavi and it leads to pallavi. Charana consists of four avartas. After the first avarta of the charanam, the first svara which is set in vilamba kala with Dirga svaras, consisting of one avarta is sung followed by second, third and other svaras set in madhyama kala each of them concluded with the first avarta of charanam. After the svara portion if finished, the other three avartas of charanam are to be sung followed by muktayi svara and then concluded with the pallavi."
Lakshana of Tana varna is formulated in above mentioned work as follows:
"It is sung in madhyama kala, words of sahityam are elongated with akara, ikara phrasings. the other aspects are the same as of Chowka varna."
Ragamalika denotes a genre of musical compositions, set to a number of ragas ("garland of ragas.") Matanga in Brihaddesi refers to certain Desi Prabandhas set to series of ragas. During medieval period Prabandhas set to series of ragas and different talas were known as Ragakadambakam (garland made of different kinds of flowers or ragas) and Raga-tala-malikas. Saringadeva mentions several Ragakadambas in Sangita Ratnakara.
Earliest composers of Ragamalikas are king Shahaji of Tanjore and Melattur Veerabhadrayya, a pioneer composer of this musical form. After him all members of Dikshitar family composed Ragamalikas.
One of the most popular Ragamalika varnas is "Valaci vacci" in nine ragas by Patnam Subramanya Iyer. Another example is Navaragamalika varnam by Kalahasti Venkatasami Raja that is composed in the ragas Nattai, Gaulai, Varali, Arabhi, Shri, Narayanagaula, Ritigaula, Bauli and Kedaram.
Ramaswami Dikshitar composed Ragamalika varna in format of pada varna for dance. He used 61 ragas (for each line of sahityam) and 46 Marga talas (having Guru and Pluta kriyas) and seven Suladi talas (V.Narasimhachary).
Daru varnam has varnam structure, and additional jathis in muktayi svara. They are very similar to Pada varnam and are eminently suited for dance choreography.
Note: Daru varnams were made famous by composer Muthiah Bhagavathar (1877-1945). He has composed many Svarajatis, Gitams, Lakshana gitams using wide range of ragas. Muttiah Bhagavatar was a versatile musician, vocalist, Harikatha actor, composer, he also played vina and mridangam. His uncle was an orthodox Vedic scholar, thus he learned Sanskrit before starting his music training under Guru Sambasiva Iyer of Tyagaraja Parampara. Mysore Vasudevacharya in his article mentions that having extensive knowledge of dance, Muttiah Bhagavatar composed Darus and Tillanas:
"Apart from his varnas and keertanas which are rich specimens of melody and emotion, I had a great admiration and liking for his tillanas and darus. Many a time, when I sang at the place, he accompanied me on the mridangam. No one could question his skill. After all, he had learnt under no less a vidvan than Narayanasamappa of Tanjore. He possessed an accurate knowledge of rhythm which explains the excellence of his tillanas and darus."
Muttiah Bhagavatar composed several Daru varnas: Mate malayadvaja pandya samjate matanga (Khamas, Adi), Balu mosamayyanura bagayara sami (Sahana, Khanda Chapu), Sannutangi shri chamundeshvari shatodari (Vasanta, Adi), and Shri raja rajeshvari shritajana palini (Kapi, Misra Chapu)
The foremost of his Daru varnams is "Mate malaya dhwaja pandya sanjate." Muktai svara of this varnam has complete line of sahitya and complete line of jathis corresponding to svaras. Darus of Muttiah Bhagavatar have no sahityam for Muktayi svara.
Vinai Sesha Iyer's darus have the solkattus as part of Muktayi svara and sahityam for the Muktayi and Ettugada svaras. Those varnas have been specially composed for dance: Devi shri rajeshvari kadambari nive karunakari (Natakurinji, Adi), Nilamegha shyamalane niruma guna sundarane (Madhuvanti, Adi), and Sarasa dala lochana mukunda unaiallal tarakam (Khamas, Adi)
Daru varnams, which have jathis and svaras in the muktayi svara portion, sometimes are referred to as "Padajathi varnas." This class of varnas is close to Svarajati, but includes the varnas composed later, in post-trinity period, when the form of varnam became prominent and famous. This indicates interesting twist of development. Varnam as a composition was developed out of Svarajati. Later on the composition was developed into the format. The format became applicable fo wide range of compositions. Finally, Svarajati itself became just one variety of varna.
Rare kind of varna is Svarasthana Pada Varnam of Ramaswami Dikshitar in Todi raga and Adi tala. The sahityam uses only the seven letters "sa, ri, ga , ma pa, dha and ni", all of Todi. This varnam was composed in praise of Manali Venkatakrishna Mudaliar and has only pallavi, anupallavi, charanam and the svaras for the last named.
Rare varnam "Entaninne" in Kamas by Subbarama Dikshitar is given in Sangita Sampradaya Pradarshini under the name of "Pada varna" (Subbarama Dikshita preferred division of varnas into Chowka and Tana, as mentioned above, thus this is the only varnam mentioned in SSP as "Pada varnam".) The first line of Ettugada pallavi is repeated after the first two Ettugada svaras, then another line of sahitya is sung followed by svaras and sahityas, then another sahitya part is sung, etc. Like this, there are two more sets of Ettugada pallavi and Ettugada svaras. On the whole it may be said that there are four different Ettugada pallavis followed by ettugada svaras. The order of rendering is specified as to complete the meaning of svara sahityas. The last svara-sahitya leads to Pallavi and the varna is concluded with the pallavi." (T.V. Subbarao)
There is one rare varnam called "Anuloma viloma varnam" composed by Wallajahpet Venkataramana Bhagavatar and Veena Kuppayyar in raga Bhairavi. Both svara and sahitya are palindromes from end to end. The opening line is "sarasaku raku sarasa".